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LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES (Details) (USD $) In Thousands, unless otherwise specified | Mar. 31, 2015 | Dec. 31, 2014 | Mar. 31, 2014 | Dec. 31, 2013
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LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES |  |  |  |  |  |
Allowance for loan losses | $ (257,738)us-gaap_FinancingReceivableAllowanceForCreditLosses |  | $ (261,679)us-gaap_FinancingReceivableAllowanceForCreditLosses |  |  |
Loans, net | 21,116,931 us-gaap_LoansAndLeasesReceivableNetReportedAmountCoveredAndNotCovered | [1] | 21,468,270 us-gaap_LoansAndLeasesReceivableNetReportedAmountCoveredAndNotCovered | [1] |  |
Non-PCI loans |  |  |  |  |  |
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES |  |  |  |  |  |
Loans, net | 19,879,588 us-gaap_LoansAndLeasesReceivableNetReportedAmountCoveredAndNotCovered / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember |  | 20,146,871 us-gaap_LoansAndLeasesReceivableNetReportedAmountCoveredAndNotCovered / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember |  |  |
PCI loans |  |  |  |  |  |
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES |  |  |  |  |  |
Loans, net | 1,237,343 us-gaap_LoansAndLeasesReceivableNetReportedAmountCoveredAndNotCovered / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesAcquiredWithDeterioratedCreditQualityMember | [1] | 1,321,399 us-gaap_LoansAndLeasesReceivableNetReportedAmountCoveredAndNotCovered / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesAcquiredWithDeterioratedCreditQualityMember | [1] |  |
Loans Receivable |  |  |  |  |  |
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES |  |  |  |  |  |
Total loans | 21,375,568 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember | [1] | 21,727,145 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember | [1] |  |
Unearned fees, premiums and discounts, net | (899)us-gaap_UnamortizedLoanCommitmentAndOriginationFeesAndUnamortizedDiscountsOrPremiums / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember | [1] | 2,804 us-gaap_UnamortizedLoanCommitmentAndOriginationFeesAndUnamortizedDiscountsOrPremiums / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember | [1] |  |
Allowance for loan losses | (257,738)us-gaap_FinancingReceivableAllowanceForCreditLosses / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember | [1] | (261,679)us-gaap_FinancingReceivableAllowanceForCreditLosses / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember | [1] | (252,136)us-gaap_FinancingReceivableAllowanceForCreditLosses / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember | (249,675)us-gaap_FinancingReceivableAllowanceForCreditLosses / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember
Loans Receivable | Non-PCI loans |  |  |  |  |  |
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES |  |  |  |  |  |
Total loans | 20,137,582 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember |  | 20,405,032 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember |  |  |
Unearned fees, premiums and discounts, net | (899)us-gaap_UnamortizedLoanCommitmentAndOriginationFeesAndUnamortizedDiscountsOrPremiums / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember |  | 2,804 us-gaap_UnamortizedLoanCommitmentAndOriginationFeesAndUnamortizedDiscountsOrPremiums / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember |  |  |
Allowance for loan losses | (257,095)us-gaap_FinancingReceivableAllowanceForCreditLosses / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember |  | (260,965)us-gaap_FinancingReceivableAllowanceForCreditLosses / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember |  | (249,934)us-gaap_FinancingReceivableAllowanceForCreditLosses / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember | (247,406)us-gaap_FinancingReceivableAllowanceForCreditLosses / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember
Loans Receivable | Non-PCI loans | Pass/Watch |  |  |  |  |  |
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES |  |  |  |  |  |
Total loans | 19,412,805 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_PassMember |  | 19,625,603 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_PassMember |  |  |
Loans Receivable | Non-PCI loans | Special Mention |  |  |  |  |  |
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES |  |  |  |  |  |
Total loans | 184,514 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SpecialMentionMember |  | 213,007 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SpecialMentionMember |  |  |
Loans Receivable | Non-PCI loans | Substandard |  |  |  |  |  |
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES |  |  |  |  |  |
Total loans | 539,783 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SubstandardMember |  | 565,834 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SubstandardMember |  |  |
Loans Receivable | Non-PCI loans | Doubtful |  |  |  |  |  |
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES |  |  |  |  |  |
Total loans | 426 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_DoubtfulMember |  | 533 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_DoubtfulMember |  |  |
Loans Receivable | Non-PCI loans | Loss |  |  |  |  |  |
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES |  |  |  |  |  |
Total loans | 54 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember / us-gaap_InternalCreditAssessmentAxis = ewbc_LossMember |  | 55 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember / us-gaap_InternalCreditAssessmentAxis = ewbc_LossMember |  |  |
Loans Receivable | PCI loans |  |  |  |  |  |
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES |  |  |  |  |  |
Total loans | 1,237,986 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesAcquiredWithDeterioratedCreditQualityMember | [1] | 1,322,113 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesAcquiredWithDeterioratedCreditQualityMember | [1] |  |
Allowance for loan losses | (643)us-gaap_FinancingReceivableAllowanceForCreditLosses / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesAcquiredWithDeterioratedCreditQualityMember | [1] | (714)us-gaap_FinancingReceivableAllowanceForCreditLosses / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesAcquiredWithDeterioratedCreditQualityMember | [1] | (2,202)us-gaap_FinancingReceivableAllowanceForCreditLosses / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesAcquiredWithDeterioratedCreditQualityMember | (2,269)us-gaap_FinancingReceivableAllowanceForCreditLosses / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesAcquiredWithDeterioratedCreditQualityMember
Loans Receivable | PCI loans | Pass/Watch |  |  |  |  |  |
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES |  |  |  |  |  |
Total loans | 1,036,513 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesAcquiredWithDeterioratedCreditQualityMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_PassMember |  | 1,089,726 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesAcquiredWithDeterioratedCreditQualityMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_PassMember |  |  |
Loans Receivable | PCI loans | Special Mention |  |  |  |  |  |
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES |  |  |  |  |  |
Total loans | 15,193 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesAcquiredWithDeterioratedCreditQualityMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SpecialMentionMember |  | 18,688 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesAcquiredWithDeterioratedCreditQualityMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SpecialMentionMember |  |  |
Loans Receivable | PCI loans | Substandard |  |  |  |  |  |
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES |  |  |  |  |  |
Total loans | 186,280 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesAcquiredWithDeterioratedCreditQualityMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SubstandardMember |  | 213,699 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesAcquiredWithDeterioratedCreditQualityMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SubstandardMember |  |  |
CRE | Loans Receivable |  |  |  |  |  |
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES |  |  |  |  |  |
Total loans | 7,045,421 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember | [1] | 6,819,513 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember | [1] |  |
CRE | Loans Receivable | Income producing |  |  |  |  |  |
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES |  |  |  |  |  |
Total loans | 6,455,177 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ewbc_IncomeProducingFinancingReceivableMember | [1] | 6,256,059 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ewbc_IncomeProducingFinancingReceivableMember | [1] |  |
CRE | Loans Receivable | Construction |  |  |  |  |  |
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES |  |  |  |  |  |
Total loans | 367,460 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember | [1] | 332,287 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember | [1] |  |
CRE | Loans Receivable | Land |  |  |  |  |  |
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES |  |  |  |  |  |
Total loans | 222,784 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ewbc_LandCommercialRealEstateMember | [1] | 231,167 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ewbc_LandCommercialRealEstateMember | [1] |  |
CRE | Loans Receivable | Non-PCI loans |  |  |  |  |  |
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES |  |  |  |  |  |
Total loans | 6,371,041 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember |  | 6,102,216 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember |  |  |
Allowance for loan losses | (69,740)us-gaap_FinancingReceivableAllowanceForCreditLosses / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember |  | (72,263)us-gaap_FinancingReceivableAllowanceForCreditLosses / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember |  | (63,627)us-gaap_FinancingReceivableAllowanceForCreditLosses / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember | (70,154)us-gaap_FinancingReceivableAllowanceForCreditLosses / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember
CRE | Loans Receivable | Non-PCI loans | Income producing |  |  |  |  |  |
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES |  |  |  |  |  |
Total loans | 5,802,931 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ewbc_IncomeProducingFinancingReceivableMember |  | 5,568,046 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ewbc_IncomeProducingFinancingReceivableMember |  |  |
CRE | Loans Receivable | Non-PCI loans | Income producing | Pass/Watch |  |  |  |  |  |
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES |  |  |  |  |  |
Total loans | 5,488,698 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ewbc_IncomeProducingFinancingReceivableMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_PassMember |  | 5,243,640 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ewbc_IncomeProducingFinancingReceivableMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_PassMember |  |  |
CRE | Loans Receivable | Non-PCI loans | Income producing | Special Mention |  |  |  |  |  |
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES |  |  |  |  |  |
Total loans | 56,245 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ewbc_IncomeProducingFinancingReceivableMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SpecialMentionMember |  | 54,673 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ewbc_IncomeProducingFinancingReceivableMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SpecialMentionMember |  |  |
CRE | Loans Receivable | Non-PCI loans | Income producing | Substandard |  |  |  |  |  |
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES |  |  |  |  |  |
Total loans | 257,988 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ewbc_IncomeProducingFinancingReceivableMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SubstandardMember |  | 269,733 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ewbc_IncomeProducingFinancingReceivableMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SubstandardMember |  |  |
CRE | Loans Receivable | Non-PCI loans | Construction |  |  |  |  |  |
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES |  |  |  |  |  |
Total loans | 358,118 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember |  | 319,843 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember |  |  |
CRE | Loans Receivable | Non-PCI loans | Construction | Pass/Watch |  |  |  |  |  |
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES |  |  |  |  |  |
Total loans | 353,799 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_PassMember |  | 310,259 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_PassMember |  |  |
CRE | Loans Receivable | Non-PCI loans | Construction | Special Mention |  |  |  |  |  |
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES |  |  |  |  |  |
Total loans | 703 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SpecialMentionMember |  | 11 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SpecialMentionMember |  |  |
CRE | Loans Receivable | Non-PCI loans | Construction | Substandard |  |  |  |  |  |
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES |  |  |  |  |  |
Total loans | 3,616 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SubstandardMember |  | 9,573 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SubstandardMember |  |  |
CRE | Loans Receivable | Non-PCI loans | Land |  |  |  |  |  |
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES |  |  |  |  |  |
Total loans | 209,992 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ewbc_LandCommercialRealEstateMember |  | 214,327 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ewbc_LandCommercialRealEstateMember |  |  |
CRE | Loans Receivable | Non-PCI loans | Land | Pass/Watch |  |  |  |  |  |
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES |  |  |  |  |  |
Total loans | 187,364 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ewbc_LandCommercialRealEstateMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_PassMember |  | 185,220 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ewbc_LandCommercialRealEstateMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_PassMember |  |  |
CRE | Loans Receivable | Non-PCI loans | Land | Special Mention |  |  |  |  |  |
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES |  |  |  |  |  |
Total loans | 5,701 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ewbc_LandCommercialRealEstateMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SpecialMentionMember |  | 5,701 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ewbc_LandCommercialRealEstateMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SpecialMentionMember |  |  |
CRE | Loans Receivable | Non-PCI loans | Land | Substandard |  |  |  |  |  |
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES |  |  |  |  |  |
Total loans | 16,927 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ewbc_LandCommercialRealEstateMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SubstandardMember |  | 23,406 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ewbc_LandCommercialRealEstateMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SubstandardMember |  |  |
CRE | Loans Receivable | PCI loans |  |  |  |  |  |
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES |  |  |  |  |  |
Total loans | 674,380 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesAcquiredWithDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember | [1] | 717,297 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesAcquiredWithDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember | [1] |  |
CRE | Loans Receivable | PCI loans | Income producing |  |  |  |  |  |
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES |  |  |  |  |  |
Total loans | 652,246 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesAcquiredWithDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ewbc_IncomeProducingFinancingReceivableMember | [1] | 688,013 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesAcquiredWithDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ewbc_IncomeProducingFinancingReceivableMember | [1] |  |
CRE | Loans Receivable | PCI loans | Income producing | Pass/Watch |  |  |  |  |  |
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES |  |  |  |  |  |
Total loans | 517,827 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesAcquiredWithDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ewbc_IncomeProducingFinancingReceivableMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_PassMember |  | 534,015 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesAcquiredWithDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ewbc_IncomeProducingFinancingReceivableMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_PassMember |  |  |
CRE | Loans Receivable | PCI loans | Income producing | Special Mention |  |  |  |  |  |
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES |  |  |  |  |  |
Total loans | 6,164 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesAcquiredWithDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ewbc_IncomeProducingFinancingReceivableMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SpecialMentionMember |  | 9,960 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesAcquiredWithDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ewbc_IncomeProducingFinancingReceivableMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SpecialMentionMember |  |  |
CRE | Loans Receivable | PCI loans | Income producing | Substandard |  |  |  |  |  |
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES |  |  |  |  |  |
Total loans | 128,255 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesAcquiredWithDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ewbc_IncomeProducingFinancingReceivableMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SubstandardMember |  | 144,038 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesAcquiredWithDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ewbc_IncomeProducingFinancingReceivableMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SubstandardMember |  |  |
CRE | Loans Receivable | PCI loans | Construction |  |  |  |  |  |
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES |  |  |  |  |  |
Total loans | 9,342 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesAcquiredWithDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember | [1] | 12,444 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesAcquiredWithDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember | [1] |  |
CRE | Loans Receivable | PCI loans | Construction | Pass/Watch |  |  |  |  |  |
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES |  |  |  |  |  |
Total loans | 585 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesAcquiredWithDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_PassMember |  | 589 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesAcquiredWithDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_PassMember |  |  |
CRE | Loans Receivable | PCI loans | Construction | Special Mention |  |  |  |  |  |
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES |  |  |  |  |  |
Total loans | 1,739 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesAcquiredWithDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SpecialMentionMember |  | 1,744 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesAcquiredWithDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SpecialMentionMember |  |  |
CRE | Loans Receivable | PCI loans | Construction | Substandard |  |  |  |  |  |
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES |  |  |  |  |  |
Total loans | 7,018 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesAcquiredWithDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SubstandardMember |  | 10,111 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesAcquiredWithDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SubstandardMember |  |  |
CRE | Loans Receivable | PCI loans | Land |  |  |  |  |  |
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES |  |  |  |  |  |
Total loans | 12,792 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesAcquiredWithDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ewbc_LandCommercialRealEstateMember | [1] | 16,840 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesAcquiredWithDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ewbc_LandCommercialRealEstateMember | [1] |  |
CRE | Loans Receivable | PCI loans | Land | Pass/Watch |  |  |  |  |  |
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES |  |  |  |  |  |
Total loans | 5,080 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesAcquiredWithDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ewbc_LandCommercialRealEstateMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_PassMember |  | 7,012 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesAcquiredWithDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ewbc_LandCommercialRealEstateMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_PassMember |  |  |
CRE | Loans Receivable | PCI loans | Land | Special Mention |  |  |  |  |  |
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES |  |  |  |  |  |
Total loans | 5,433 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesAcquiredWithDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ewbc_LandCommercialRealEstateMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SpecialMentionMember |  | 5,391 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesAcquiredWithDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ewbc_LandCommercialRealEstateMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SpecialMentionMember |  |  |
CRE | Loans Receivable | PCI loans | Land | Substandard |  |  |  |  |  |
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES |  |  |  |  |  |
Total loans | 2,279 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesAcquiredWithDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ewbc_LandCommercialRealEstateMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SubstandardMember |  | 4,437 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesAcquiredWithDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ewbc_LandCommercialRealEstateMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SubstandardMember |  |  |
C&I | Loans Receivable |  |  |  |  |  |
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES |  |  |  |  |  |
Total loans | 7,720,764 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialPortfolioSegmentMember | [1] | 8,077,201 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialPortfolioSegmentMember | [1] |  |
C&I | Loans Receivable | Commercial business |  |  |  |  |  |
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES |  |  |  |  |  |
Total loans | 6,871,450 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialPortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ewbc_CommercialBusinessMember | [1] | 7,181,189 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialPortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ewbc_CommercialBusinessMember | [1] |  |
C&I | Loans Receivable | Trade finance |  |  |  |  |  |
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES |  |  |  |  |  |
Total loans | 849,314 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialPortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ewbc_TradeFinanceMember | [1] | 896,012 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialPortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ewbc_TradeFinanceMember | [1] |  |
C&I | Loans Receivable | Non-PCI loans |  |  |  |  |  |
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES |  |  |  |  |  |
Total loans | 7,643,239 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialPortfolioSegmentMember |  | 7,987,581 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialPortfolioSegmentMember |  |  |
Allowance for loan losses | (133,914)us-gaap_FinancingReceivableAllowanceForCreditLosses / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialPortfolioSegmentMember |  | (134,598)us-gaap_FinancingReceivableAllowanceForCreditLosses / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialPortfolioSegmentMember |  | (127,156)us-gaap_FinancingReceivableAllowanceForCreditLosses / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialPortfolioSegmentMember | (115,184)us-gaap_FinancingReceivableAllowanceForCreditLosses / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialPortfolioSegmentMember
C&I | Loans Receivable | Non-PCI loans | Commercial business |  |  |  |  |  |
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES |  |  |  |  |  |
Total loans | 6,799,149 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialPortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ewbc_CommercialBusinessMember |  | 7,097,853 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialPortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ewbc_CommercialBusinessMember |  |  |
C&I | Loans Receivable | Non-PCI loans | Commercial business | Pass/Watch |  |  |  |  |  |
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES |  |  |  |  |  |
Total loans | 6,573,081 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialPortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ewbc_CommercialBusinessMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_PassMember |  | 6,836,914 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialPortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ewbc_CommercialBusinessMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_PassMember |  |  |
C&I | Loans Receivable | Non-PCI loans | Commercial business | Special Mention |  |  |  |  |  |
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES |  |  |  |  |  |
Total loans | 93,302 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialPortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ewbc_CommercialBusinessMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SpecialMentionMember |  | 130,319 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialPortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ewbc_CommercialBusinessMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SpecialMentionMember |  |  |
C&I | Loans Receivable | Non-PCI loans | Commercial business | Substandard |  |  |  |  |  |
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES |  |  |  |  |  |
Total loans | 132,286 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialPortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ewbc_CommercialBusinessMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SubstandardMember |  | 130,032 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialPortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ewbc_CommercialBusinessMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SubstandardMember |  |  |
C&I | Loans Receivable | Non-PCI loans | Commercial business | Doubtful |  |  |  |  |  |
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES |  |  |  |  |  |
Total loans | 426 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialPortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ewbc_CommercialBusinessMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_DoubtfulMember |  | 533 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialPortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ewbc_CommercialBusinessMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_DoubtfulMember |  |  |
C&I | Loans Receivable | Non-PCI loans | Commercial business | Loss |  |  |  |  |  |
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES |  |  |  |  |  |
Total loans | 54 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialPortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ewbc_CommercialBusinessMember / us-gaap_InternalCreditAssessmentAxis = ewbc_LossMember |  | 55 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialPortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ewbc_CommercialBusinessMember / us-gaap_InternalCreditAssessmentAxis = ewbc_LossMember |  |  |
C&I | Loans Receivable | Non-PCI loans | Trade finance |  |  |  |  |  |
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES |  |  |  |  |  |
Total loans | 844,090 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialPortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ewbc_TradeFinanceMember |  | 889,728 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialPortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ewbc_TradeFinanceMember |  |  |
C&I | Loans Receivable | Non-PCI loans | Trade finance | Pass/Watch |  |  |  |  |  |
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES |  |  |  |  |  |
Total loans | 788,864 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialPortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ewbc_TradeFinanceMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_PassMember |  | 845,889 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialPortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ewbc_TradeFinanceMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_PassMember |  |  |
C&I | Loans Receivable | Non-PCI loans | Trade finance | Special Mention |  |  |  |  |  |
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES |  |  |  |  |  |
Total loans | 19,726 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialPortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ewbc_TradeFinanceMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SpecialMentionMember |  | 13,031 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialPortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ewbc_TradeFinanceMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SpecialMentionMember |  |  |
C&I | Loans Receivable | Non-PCI loans | Trade finance | Substandard |  |  |  |  |  |
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES |  |  |  |  |  |
Total loans | 35,500 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialPortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ewbc_TradeFinanceMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SubstandardMember |  | 30,808 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialPortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ewbc_TradeFinanceMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SubstandardMember |  |  |
C&I | Loans Receivable | PCI loans |  |  |  |  |  |
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES |  |  |  |  |  |
Total loans | 77,525 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesAcquiredWithDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialPortfolioSegmentMember | [1] | 89,620 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesAcquiredWithDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialPortfolioSegmentMember | [1] |  |
C&I | Loans Receivable | PCI loans | Commercial business |  |  |  |  |  |
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES |  |  |  |  |  |
Total loans | 72,301 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesAcquiredWithDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialPortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ewbc_CommercialBusinessMember | [1] | 83,336 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesAcquiredWithDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialPortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ewbc_CommercialBusinessMember | [1] |  |
C&I | Loans Receivable | PCI loans | Commercial business | Pass/Watch |  |  |  |  |  |
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES |  |  |  |  |  |
Total loans | 62,858 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesAcquiredWithDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialPortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ewbc_CommercialBusinessMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_PassMember |  | 70,586 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesAcquiredWithDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialPortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ewbc_CommercialBusinessMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_PassMember |  |  |
C&I | Loans Receivable | PCI loans | Commercial business | Special Mention |  |  |  |  |  |
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES |  |  |  |  |  |
Total loans | 997 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesAcquiredWithDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialPortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ewbc_CommercialBusinessMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SpecialMentionMember |  | 1,103 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesAcquiredWithDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialPortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ewbc_CommercialBusinessMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SpecialMentionMember |  |  |
C&I | Loans Receivable | PCI loans | Commercial business | Substandard |  |  |  |  |  |
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES |  |  |  |  |  |
Total loans | 8,446 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesAcquiredWithDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialPortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ewbc_CommercialBusinessMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SubstandardMember |  | 11,647 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesAcquiredWithDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialPortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ewbc_CommercialBusinessMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SubstandardMember |  |  |
C&I | Loans Receivable | PCI loans | Trade finance |  |  |  |  |  |
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES |  |  |  |  |  |
Total loans | 5,224 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesAcquiredWithDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialPortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ewbc_TradeFinanceMember | [1] | 6,284 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesAcquiredWithDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialPortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ewbc_TradeFinanceMember | [1] |  |
C&I | Loans Receivable | PCI loans | Trade finance | Pass/Watch |  |  |  |  |  |
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES |  |  |  |  |  |
Total loans | 3,535 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesAcquiredWithDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialPortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ewbc_TradeFinanceMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_PassMember |  | 4,620 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesAcquiredWithDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialPortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ewbc_TradeFinanceMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_PassMember |  |  |
C&I | Loans Receivable | PCI loans | Trade finance | Substandard |  |  |  |  |  |
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES |  |  |  |  |  |
Total loans | 1,689 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesAcquiredWithDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialPortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ewbc_TradeFinanceMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SubstandardMember |  | 1,664 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesAcquiredWithDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialPortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ewbc_TradeFinanceMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SubstandardMember |  |  |
Residential | Loans Receivable |  |  |  |  |  |
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES |  |  |  |  |  |
Total loans | 4,997,219 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_ResidentialPortfolioSegmentMember | [1] | 5,316,689 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_ResidentialPortfolioSegmentMember | [1] |  |
Residential | Loans Receivable | Single-family |  |  |  |  |  |
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES |  |  |  |  |  |
Total loans | 3,512,794 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_ResidentialPortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ewbc_ResidentialSingleFamilyMember | [1] | 3,866,781 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_ResidentialPortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ewbc_ResidentialSingleFamilyMember | [1] |  |
Residential | Loans Receivable | Multifamily |  |  |  |  |  |
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES |  |  |  |  |  |
Total loans | 1,484,425 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_ResidentialPortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ewbc_ResidentialMultifamilyMember | [1] | 1,449,908 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_ResidentialPortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ewbc_ResidentialMultifamilyMember | [1] |  |
Residential | Loans Receivable | Non-PCI loans |  |  |  |  |  |
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES |  |  |  |  |  |
Total loans | 4,539,134 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_ResidentialPortfolioSegmentMember |  | 4,831,279 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_ResidentialPortfolioSegmentMember |  |  |
Allowance for loan losses | (42,990)us-gaap_FinancingReceivableAllowanceForCreditLosses / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_ResidentialPortfolioSegmentMember |  | (43,856)us-gaap_FinancingReceivableAllowanceForCreditLosses / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_ResidentialPortfolioSegmentMember |  | (47,995)us-gaap_FinancingReceivableAllowanceForCreditLosses / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_ResidentialPortfolioSegmentMember | (50,716)us-gaap_FinancingReceivableAllowanceForCreditLosses / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_ResidentialPortfolioSegmentMember
Residential | Loans Receivable | Non-PCI loans | Single-family |  |  |  |  |  |
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES |  |  |  |  |  |
Total loans | 3,298,775 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_ResidentialPortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ewbc_ResidentialSingleFamilyMember |  | 3,647,262 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_ResidentialPortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ewbc_ResidentialSingleFamilyMember |  |  |
Residential | Loans Receivable | Non-PCI loans | Single-family | Pass/Watch |  |  |  |  |  |
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES |  |  |  |  |  |
Total loans | 3,277,085 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_ResidentialPortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ewbc_ResidentialSingleFamilyMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_PassMember |  | 3,627,491 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_ResidentialPortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ewbc_ResidentialSingleFamilyMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_PassMember |  |  |
Residential | Loans Receivable | Non-PCI loans | Single-family | Special Mention |  |  |  |  |  |
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES |  |  |  |  |  |
Total loans | 3,595 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_ResidentialPortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ewbc_ResidentialSingleFamilyMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SpecialMentionMember |  | 3,143 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_ResidentialPortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ewbc_ResidentialSingleFamilyMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SpecialMentionMember |  |  |
Residential | Loans Receivable | Non-PCI loans | Single-family | Substandard |  |  |  |  |  |
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES |  |  |  |  |  |
Total loans | 18,095 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_ResidentialPortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ewbc_ResidentialSingleFamilyMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SubstandardMember |  | 16,628 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_ResidentialPortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ewbc_ResidentialSingleFamilyMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SubstandardMember |  |  |
Residential | Loans Receivable | Non-PCI loans | Multifamily |  |  |  |  |  |
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES |  |  |  |  |  |
Total loans | 1,240,359 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_ResidentialPortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ewbc_ResidentialMultifamilyMember |  | 1,184,017 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_ResidentialPortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ewbc_ResidentialMultifamilyMember |  |  |
Residential | Loans Receivable | Non-PCI loans | Multifamily | Pass/Watch |  |  |  |  |  |
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES |  |  |  |  |  |
Total loans | 1,162,798 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_ResidentialPortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ewbc_ResidentialMultifamilyMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_PassMember |  | 1,095,982 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_ResidentialPortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ewbc_ResidentialMultifamilyMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_PassMember |  |  |
Residential | Loans Receivable | Non-PCI loans | Multifamily | Special Mention |  |  |  |  |  |
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES |  |  |  |  |  |
Total loans | 4,906 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_ResidentialPortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ewbc_ResidentialMultifamilyMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SpecialMentionMember |  | 5,124 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_ResidentialPortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ewbc_ResidentialMultifamilyMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SpecialMentionMember |  |  |
Residential | Loans Receivable | Non-PCI loans | Multifamily | Substandard |  |  |  |  |  |
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES |  |  |  |  |  |
Total loans | 72,655 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_ResidentialPortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ewbc_ResidentialMultifamilyMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SubstandardMember |  | 82,911 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_ResidentialPortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ewbc_ResidentialMultifamilyMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SubstandardMember |  |  |
Residential | Loans Receivable | PCI loans |  |  |  |  |  |
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES |  |  |  |  |  |
Total loans | 458,085 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesAcquiredWithDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_ResidentialPortfolioSegmentMember | [1] | 485,410 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesAcquiredWithDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_ResidentialPortfolioSegmentMember | [1] |  |
Residential | Loans Receivable | PCI loans | Single-family |  |  |  |  |  |
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES |  |  |  |  |  |
Total loans | 214,019 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesAcquiredWithDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_ResidentialPortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ewbc_ResidentialSingleFamilyMember | [1] | 219,519 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesAcquiredWithDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_ResidentialPortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ewbc_ResidentialSingleFamilyMember | [1] |  |
Residential | Loans Receivable | PCI loans | Single-family | Pass/Watch |  |  |  |  |  |
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES |  |  |  |  |  |
Total loans | 208,238 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesAcquiredWithDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_ResidentialPortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ewbc_ResidentialSingleFamilyMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_PassMember |  | 213,829 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesAcquiredWithDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_ResidentialPortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ewbc_ResidentialSingleFamilyMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_PassMember |  |  |
Residential | Loans Receivable | PCI loans | Single-family | Special Mention |  |  |  |  |  |
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES |  |  |  |  |  |
Total loans | 745 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesAcquiredWithDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_ResidentialPortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ewbc_ResidentialSingleFamilyMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SpecialMentionMember |  | 374 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesAcquiredWithDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_ResidentialPortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ewbc_ResidentialSingleFamilyMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SpecialMentionMember |  |  |
Residential | Loans Receivable | PCI loans | Single-family | Substandard |  |  |  |  |  |
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES |  |  |  |  |  |
Total loans | 5,036 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesAcquiredWithDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_ResidentialPortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ewbc_ResidentialSingleFamilyMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SubstandardMember |  | 5,316 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesAcquiredWithDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_ResidentialPortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ewbc_ResidentialSingleFamilyMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SubstandardMember |  |  |
Residential | Loans Receivable | PCI loans | Multifamily |  |  |  |  |  |
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES |  |  |  |  |  |
Total loans | 244,066 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesAcquiredWithDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_ResidentialPortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ewbc_ResidentialMultifamilyMember | [1] | 265,891 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesAcquiredWithDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_ResidentialPortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ewbc_ResidentialMultifamilyMember | [1] |  |
Residential | Loans Receivable | PCI loans | Multifamily | Pass/Watch |  |  |  |  |  |
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES |  |  |  |  |  |
Total loans | 211,060 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesAcquiredWithDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_ResidentialPortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ewbc_ResidentialMultifamilyMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_PassMember |  | 230,049 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesAcquiredWithDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_ResidentialPortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ewbc_ResidentialMultifamilyMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_PassMember |  |  |
Residential | Loans Receivable | PCI loans | Multifamily | Substandard |  |  |  |  |  |
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES |  |  |  |  |  |
Total loans | 33,006 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesAcquiredWithDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_ResidentialPortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ewbc_ResidentialMultifamilyMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SubstandardMember |  | 35,842 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesAcquiredWithDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_ResidentialPortfolioSegmentMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = ewbc_ResidentialMultifamilyMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SubstandardMember |  |  |
Consumer | Loans Receivable |  |  |  |  |  |
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES |  |  |  |  |  |
Total loans | 1,612,164 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_ConsumerPortfolioSegmentMember | [1] | 1,513,742 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_ConsumerPortfolioSegmentMember | [1] |  |
Consumer | Loans Receivable | Non-PCI loans |  |  |  |  |  |
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES |  |  |  |  |  |
Total loans | 1,584,168 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_ConsumerPortfolioSegmentMember |  | 1,483,956 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_ConsumerPortfolioSegmentMember |  |  |
Allowance for loan losses | (10,451)us-gaap_FinancingReceivableAllowanceForCreditLosses / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_ConsumerPortfolioSegmentMember |  | (10,248)us-gaap_FinancingReceivableAllowanceForCreditLosses / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_ConsumerPortfolioSegmentMember |  | (11,156)us-gaap_FinancingReceivableAllowanceForCreditLosses / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_ConsumerPortfolioSegmentMember | (11,352)us-gaap_FinancingReceivableAllowanceForCreditLosses / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_ConsumerPortfolioSegmentMember
Consumer | Loans Receivable | Non-PCI loans | Pass/Watch |  |  |  |  |  |
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES |  |  |  |  |  |
Total loans | 1,581,116 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_ConsumerPortfolioSegmentMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_PassMember |  | 1,480,208 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_ConsumerPortfolioSegmentMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_PassMember |  |  |
Consumer | Loans Receivable | Non-PCI loans | Special Mention |  |  |  |  |  |
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES |  |  |  |  |  |
Total loans | 336 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_ConsumerPortfolioSegmentMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SpecialMentionMember |  | 1,005 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_ConsumerPortfolioSegmentMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SpecialMentionMember |  |  |
Consumer | Loans Receivable | Non-PCI loans | Substandard |  |  |  |  |  |
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES |  |  |  |  |  |
Total loans | 2,716 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_ConsumerPortfolioSegmentMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SubstandardMember |  | 2,743 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_ConsumerPortfolioSegmentMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SubstandardMember |  |  |
Consumer | Loans Receivable | PCI loans |  |  |  |  |  |
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES |  |  |  |  |  |
Total loans | 27,996 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesAcquiredWithDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_ConsumerPortfolioSegmentMember | [1] | 29,786 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesAcquiredWithDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_ConsumerPortfolioSegmentMember | [1] |  |
Consumer | Loans Receivable | PCI loans | Pass/Watch |  |  |  |  |  |
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES |  |  |  |  |  |
Total loans | 27,330 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesAcquiredWithDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_ConsumerPortfolioSegmentMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_PassMember |  | 29,026 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesAcquiredWithDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_ConsumerPortfolioSegmentMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_PassMember |  |  |
Consumer | Loans Receivable | PCI loans | Special Mention |  |  |  |  |  |
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES |  |  |  |  |  |
Total loans | 115 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesAcquiredWithDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_ConsumerPortfolioSegmentMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SpecialMentionMember |  | 116 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesAcquiredWithDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_ConsumerPortfolioSegmentMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SpecialMentionMember |  |  |
Consumer | Loans Receivable | PCI loans | Substandard |  |  |  |  |  |
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES |  |  |  |  |  |
Total loans | $ 551 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesAcquiredWithDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_ConsumerPortfolioSegmentMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SubstandardMember |  | $ 644 us-gaap_NotesReceivableGross / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember / us-gaap_FairValueByAssetClassAxis = ewbc_ReceivablesAcquiredWithDeterioratedCreditQualityMember / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_ConsumerPortfolioSegmentMember / us-gaap_InternalCreditAssessmentAxis = us-gaap_SubstandardMember |  |  |
[1] | Loans net of ASC 310-30 discount.

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