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v2.4.1.9

NON-COVERED LOANS AND ALLOWANCE FOR LOAN LOSSES (Details 12) (USD $) In Thousands, unless otherwise specified | 12 Months Ended
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Dec. 31, 2014 | Dec. 31, 2013 | Dec. 31, 2012
Financing Receivable Allowance for Credit Losses Roll Forward |  |  |  |
Provision for (reversal of) loan losses | $ 49,158 us-gaap_ProvisionForLoanAndLeaseLosses |  | $ 22,364 us-gaap_ProvisionForLoanAndLeaseLosses | $ 65,184 us-gaap_ProvisionForLoanAndLeaseLosses
Non-covered loans |  |  |  |
Financing Receivable Allowance for Credit Losses Roll Forward |  |  |  |
Beginning balance | 241,930 us-gaap_FinancingReceivableAllowanceForCreditLosses / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember |  | 229,382 us-gaap_FinancingReceivableAllowanceForCreditLosses / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember | 209,876 us-gaap_FinancingReceivableAllowanceForCreditLosses / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember
Allowance for unfunded loan commitments and letters of credit | (1,575)ewbc_FinancingReceivableAllowanceForCreditLossesAllowanceForUnfundedLoanCommitmentsAndLettersOfCredit / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember |  | (2,157)ewbc_FinancingReceivableAllowanceForCreditLossesAllowanceForUnfundedLoanCommitmentsAndLettersOfCredit / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember | 1,563 ewbc_FinancingReceivableAllowanceForCreditLossesAllowanceForUnfundedLoanCommitmentsAndLettersOfCredit / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember
Provision for (reversal of) loan losses | 44,125 us-gaap_ProvisionForLoanAndLeaseLosses / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember |  | 18,336 us-gaap_ProvisionForLoanAndLeaseLosses / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember | 60,168 us-gaap_ProvisionForLoanAndLeaseLosses / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember
Charge-offs | (39,782)us-gaap_FinancingReceivableAllowanceForCreditLossesWriteOffs / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember |  | (16,344)us-gaap_FinancingReceivableAllowanceForCreditLossesWriteOffs / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember | (58,402)us-gaap_FinancingReceivableAllowanceForCreditLossesWriteOffs / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember
Recoveries | 13,476 us-gaap_AllowanceForLoanAndLeaseLossRecoveryOfBadDebts / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember |  | 12,713 us-gaap_AllowanceForLoanAndLeaseLossRecoveryOfBadDebts / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember | 16,177 us-gaap_AllowanceForLoanAndLeaseLossRecoveryOfBadDebts / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember
Net (charge-offs) recoveries | (26,306)us-gaap_AllowanceForLoanAndLeaseLossesWriteoffsNet / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember |  | (3,631)us-gaap_AllowanceForLoanAndLeaseLossesWriteoffsNet / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember | (42,225)us-gaap_AllowanceForLoanAndLeaseLossesWriteoffsNet / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember
Ending balance | 258,174 us-gaap_FinancingReceivableAllowanceForCreditLosses / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember |  | 241,930 us-gaap_FinancingReceivableAllowanceForCreditLosses / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember | 229,382 us-gaap_FinancingReceivableAllowanceForCreditLosses / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember
Ending balance allocated to: |  |  |  |
Loans individually evaluated for impairment | 19,464 us-gaap_FinancingReceivableAllowanceForCreditLossesIndividuallyEvaluatedForImpairment1 / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember |  | 24,143 us-gaap_FinancingReceivableAllowanceForCreditLossesIndividuallyEvaluatedForImpairment1 / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember | 11,527 us-gaap_FinancingReceivableAllowanceForCreditLossesIndividuallyEvaluatedForImpairment1 / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember
Loans collectively evaluated for impairment | 238,420 us-gaap_FinancingReceivableAllowanceForCreditLossesCollectivelyEvaluatedForImpairment / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember |  | 217,787 us-gaap_FinancingReceivableAllowanceForCreditLossesCollectivelyEvaluatedForImpairment / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember | 217,855 us-gaap_FinancingReceivableAllowanceForCreditLossesCollectivelyEvaluatedForImpairment / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember
Acquired with deteriorated credit quality | 290 us-gaap_FinancingReceivableAllowanceForCreditLossesAcquiredWithDeterioratedCreditQuality / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember |  |  |
Ending balance | 258,174 us-gaap_FinancingReceivableAllowanceForCreditLosses / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember |  | 241,930 us-gaap_FinancingReceivableAllowanceForCreditLosses / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember | 229,382 us-gaap_FinancingReceivableAllowanceForCreditLosses / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember
Non-covered loans | MetroCorp |  |  |  |
Financing Receivable Allowance for Credit Losses Roll Forward |  |  |  |
Charge-offs | (523)us-gaap_FinancingReceivableAllowanceForCreditLossesWriteOffs / us-gaap_BusinessAcquisitionAxis = ewbc_MetroCorpMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember |  |  |
CRE | Non-covered loans |  |  |  |
Financing Receivable Allowance for Credit Losses Roll Forward |  |  |  |
Beginning balance | 64,677 us-gaap_FinancingReceivableAllowanceForCreditLosses / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember |  | 69,856 us-gaap_FinancingReceivableAllowanceForCreditLosses / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember | 66,457 us-gaap_FinancingReceivableAllowanceForCreditLosses / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember
Provision for (reversal of) loan losses | 6,107 us-gaap_ProvisionForLoanAndLeaseLosses / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember |  | (6,615)us-gaap_ProvisionForLoanAndLeaseLosses / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember | 20,977 us-gaap_ProvisionForLoanAndLeaseLosses / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember
Charge-offs | (3,294)us-gaap_FinancingReceivableAllowanceForCreditLossesWriteOffs / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember | [1] | (3,357)us-gaap_FinancingReceivableAllowanceForCreditLossesWriteOffs / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember | (27,060)us-gaap_FinancingReceivableAllowanceForCreditLossesWriteOffs / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember
Recoveries | 1,982 us-gaap_AllowanceForLoanAndLeaseLossRecoveryOfBadDebts / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember |  | 4,793 us-gaap_AllowanceForLoanAndLeaseLossRecoveryOfBadDebts / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember | 9,482 us-gaap_AllowanceForLoanAndLeaseLossRecoveryOfBadDebts / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember
Net (charge-offs) recoveries | (1,312)us-gaap_AllowanceForLoanAndLeaseLossesWriteoffsNet / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember |  | 1,436 us-gaap_AllowanceForLoanAndLeaseLossesWriteoffsNet / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember | (17,578)us-gaap_AllowanceForLoanAndLeaseLossesWriteoffsNet / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember
Ending balance | 69,472 us-gaap_FinancingReceivableAllowanceForCreditLosses / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember |  | 64,677 us-gaap_FinancingReceivableAllowanceForCreditLosses / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember | 69,856 us-gaap_FinancingReceivableAllowanceForCreditLosses / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember
Ending balance allocated to: |  |  |  |
Loans individually evaluated for impairment | 3,487 us-gaap_FinancingReceivableAllowanceForCreditLossesIndividuallyEvaluatedForImpairment1 / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember |  | 8,058 us-gaap_FinancingReceivableAllowanceForCreditLossesIndividuallyEvaluatedForImpairment1 / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember | 5,561 us-gaap_FinancingReceivableAllowanceForCreditLossesIndividuallyEvaluatedForImpairment1 / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember
Loans collectively evaluated for impairment | 65,695 us-gaap_FinancingReceivableAllowanceForCreditLossesCollectivelyEvaluatedForImpairment / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember |  | 56,619 us-gaap_FinancingReceivableAllowanceForCreditLossesCollectivelyEvaluatedForImpairment / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember | 64,295 us-gaap_FinancingReceivableAllowanceForCreditLossesCollectivelyEvaluatedForImpairment / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember
Acquired with deteriorated credit quality | 290 us-gaap_FinancingReceivableAllowanceForCreditLossesAcquiredWithDeterioratedCreditQuality / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember |  |  |
Ending balance | 69,472 us-gaap_FinancingReceivableAllowanceForCreditLosses / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember |  | 64,677 us-gaap_FinancingReceivableAllowanceForCreditLosses / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember | 69,856 us-gaap_FinancingReceivableAllowanceForCreditLosses / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember
C&I | Non-covered loans |  |  |  |
Financing Receivable Allowance for Credit Losses Roll Forward |  |  |  |
Beginning balance | 115,184 us-gaap_FinancingReceivableAllowanceForCreditLosses / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialPortfolioSegmentMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember |  | 105,376 us-gaap_FinancingReceivableAllowanceForCreditLosses / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialPortfolioSegmentMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember | 87,020 us-gaap_FinancingReceivableAllowanceForCreditLosses / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialPortfolioSegmentMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember
Provision for (reversal of) loan losses | 40,371 us-gaap_ProvisionForLoanAndLeaseLosses / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialPortfolioSegmentMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember |  | 12,821 us-gaap_ProvisionForLoanAndLeaseLosses / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialPortfolioSegmentMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember | 35,204 us-gaap_ProvisionForLoanAndLeaseLosses / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialPortfolioSegmentMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember
Charge-offs | (29,592)us-gaap_FinancingReceivableAllowanceForCreditLossesWriteOffs / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialPortfolioSegmentMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember |  | (7,405)us-gaap_FinancingReceivableAllowanceForCreditLossesWriteOffs / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialPortfolioSegmentMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember | (21,818)us-gaap_FinancingReceivableAllowanceForCreditLossesWriteOffs / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialPortfolioSegmentMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember
Recoveries | 8,635 us-gaap_AllowanceForLoanAndLeaseLossRecoveryOfBadDebts / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialPortfolioSegmentMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember |  | 4,392 us-gaap_AllowanceForLoanAndLeaseLossRecoveryOfBadDebts / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialPortfolioSegmentMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember | 4,970 us-gaap_AllowanceForLoanAndLeaseLossRecoveryOfBadDebts / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialPortfolioSegmentMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember
Net (charge-offs) recoveries | (20,957)us-gaap_AllowanceForLoanAndLeaseLossesWriteoffsNet / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialPortfolioSegmentMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember |  | (3,013)us-gaap_AllowanceForLoanAndLeaseLossesWriteoffsNet / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialPortfolioSegmentMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember | (16,848)us-gaap_AllowanceForLoanAndLeaseLossesWriteoffsNet / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialPortfolioSegmentMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember
Ending balance | 134,598 us-gaap_FinancingReceivableAllowanceForCreditLosses / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialPortfolioSegmentMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember |  | 115,184 us-gaap_FinancingReceivableAllowanceForCreditLosses / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialPortfolioSegmentMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember | 105,376 us-gaap_FinancingReceivableAllowanceForCreditLosses / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialPortfolioSegmentMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember
Ending balance allocated to: |  |  |  |
Loans individually evaluated for impairment | 15,202 us-gaap_FinancingReceivableAllowanceForCreditLossesIndividuallyEvaluatedForImpairment1 / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialPortfolioSegmentMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember |  | 14,539 us-gaap_FinancingReceivableAllowanceForCreditLossesIndividuallyEvaluatedForImpairment1 / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialPortfolioSegmentMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember | 2,835 us-gaap_FinancingReceivableAllowanceForCreditLossesIndividuallyEvaluatedForImpairment1 / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialPortfolioSegmentMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember
Loans collectively evaluated for impairment | 119,396 us-gaap_FinancingReceivableAllowanceForCreditLossesCollectivelyEvaluatedForImpairment / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialPortfolioSegmentMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember |  | 100,645 us-gaap_FinancingReceivableAllowanceForCreditLossesCollectivelyEvaluatedForImpairment / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialPortfolioSegmentMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember | 102,541 us-gaap_FinancingReceivableAllowanceForCreditLossesCollectivelyEvaluatedForImpairment / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialPortfolioSegmentMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember
Ending balance | 134,598 us-gaap_FinancingReceivableAllowanceForCreditLosses / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialPortfolioSegmentMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember |  | 115,184 us-gaap_FinancingReceivableAllowanceForCreditLosses / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialPortfolioSegmentMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember | 105,376 us-gaap_FinancingReceivableAllowanceForCreditLosses / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_CommercialPortfolioSegmentMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember
Residential | Non-covered loans |  |  |  |
Financing Receivable Allowance for Credit Losses Roll Forward |  |  |  |
Beginning balance | 50,717 us-gaap_FinancingReceivableAllowanceForCreditLosses / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_ResidentialPortfolioSegmentMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember |  | 49,349 us-gaap_FinancingReceivableAllowanceForCreditLosses / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_ResidentialPortfolioSegmentMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember | 52,180 us-gaap_FinancingReceivableAllowanceForCreditLosses / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_ResidentialPortfolioSegmentMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember
Provision for (reversal of) loan losses | (8,168)us-gaap_ProvisionForLoanAndLeaseLosses / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_ResidentialPortfolioSegmentMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember |  | 1,918 us-gaap_ProvisionForLoanAndLeaseLosses / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_ResidentialPortfolioSegmentMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember | 3,255 us-gaap_ProvisionForLoanAndLeaseLosses / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_ResidentialPortfolioSegmentMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember
Charge-offs | (1,103)us-gaap_FinancingReceivableAllowanceForCreditLossesWriteOffs / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_ResidentialPortfolioSegmentMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember |  | (3,197)us-gaap_FinancingReceivableAllowanceForCreditLossesWriteOffs / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_ResidentialPortfolioSegmentMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember | (7,700)us-gaap_FinancingReceivableAllowanceForCreditLossesWriteOffs / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_ResidentialPortfolioSegmentMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember
Recoveries | 2,410 us-gaap_AllowanceForLoanAndLeaseLossRecoveryOfBadDebts / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_ResidentialPortfolioSegmentMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember |  | 2,647 us-gaap_AllowanceForLoanAndLeaseLossRecoveryOfBadDebts / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_ResidentialPortfolioSegmentMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember | 1,614 us-gaap_AllowanceForLoanAndLeaseLossRecoveryOfBadDebts / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_ResidentialPortfolioSegmentMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember
Net (charge-offs) recoveries | 1,307 us-gaap_AllowanceForLoanAndLeaseLossesWriteoffsNet / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_ResidentialPortfolioSegmentMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember |  | (550)us-gaap_AllowanceForLoanAndLeaseLossesWriteoffsNet / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_ResidentialPortfolioSegmentMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember | (6,086)us-gaap_AllowanceForLoanAndLeaseLossesWriteoffsNet / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_ResidentialPortfolioSegmentMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember
Ending balance | 43,856 us-gaap_FinancingReceivableAllowanceForCreditLosses / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_ResidentialPortfolioSegmentMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember |  | 50,717 us-gaap_FinancingReceivableAllowanceForCreditLosses / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_ResidentialPortfolioSegmentMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember | 49,349 us-gaap_FinancingReceivableAllowanceForCreditLosses / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_ResidentialPortfolioSegmentMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember
Ending balance allocated to: |  |  |  |
Loans individually evaluated for impairment | 774 us-gaap_FinancingReceivableAllowanceForCreditLossesIndividuallyEvaluatedForImpairment1 / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_ResidentialPortfolioSegmentMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember |  | 1,546 us-gaap_FinancingReceivableAllowanceForCreditLossesIndividuallyEvaluatedForImpairment1 / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_ResidentialPortfolioSegmentMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember | 3,131 us-gaap_FinancingReceivableAllowanceForCreditLossesIndividuallyEvaluatedForImpairment1 / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_ResidentialPortfolioSegmentMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember
Loans collectively evaluated for impairment | 43,082 us-gaap_FinancingReceivableAllowanceForCreditLossesCollectivelyEvaluatedForImpairment / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_ResidentialPortfolioSegmentMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember |  | 49,171 us-gaap_FinancingReceivableAllowanceForCreditLossesCollectivelyEvaluatedForImpairment / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_ResidentialPortfolioSegmentMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember | 46,218 us-gaap_FinancingReceivableAllowanceForCreditLossesCollectivelyEvaluatedForImpairment / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_ResidentialPortfolioSegmentMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember
Ending balance | 43,856 us-gaap_FinancingReceivableAllowanceForCreditLosses / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_ResidentialPortfolioSegmentMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember |  | 50,717 us-gaap_FinancingReceivableAllowanceForCreditLosses / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_ResidentialPortfolioSegmentMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember | 49,349 us-gaap_FinancingReceivableAllowanceForCreditLosses / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_ResidentialPortfolioSegmentMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember
Consumer | Non-covered loans |  |  |  |
Financing Receivable Allowance for Credit Losses Roll Forward |  |  |  |
Beginning balance | 11,352 us-gaap_FinancingReceivableAllowanceForCreditLosses / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_ConsumerPortfolioSegmentMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember |  | 4,801 us-gaap_FinancingReceivableAllowanceForCreditLosses / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_ConsumerPortfolioSegmentMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember | 4,219 us-gaap_FinancingReceivableAllowanceForCreditLosses / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_ConsumerPortfolioSegmentMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember
Provision for (reversal of) loan losses | 4,240 us-gaap_ProvisionForLoanAndLeaseLosses / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_ConsumerPortfolioSegmentMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember |  | 8,055 us-gaap_ProvisionForLoanAndLeaseLosses / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_ConsumerPortfolioSegmentMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember | 2,295 us-gaap_ProvisionForLoanAndLeaseLosses / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_ConsumerPortfolioSegmentMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember
Charge-offs | (5,793)us-gaap_FinancingReceivableAllowanceForCreditLossesWriteOffs / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_ConsumerPortfolioSegmentMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember |  | (2,385)us-gaap_FinancingReceivableAllowanceForCreditLossesWriteOffs / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_ConsumerPortfolioSegmentMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember | (1,824)us-gaap_FinancingReceivableAllowanceForCreditLossesWriteOffs / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_ConsumerPortfolioSegmentMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember
Recoveries | 449 us-gaap_AllowanceForLoanAndLeaseLossRecoveryOfBadDebts / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_ConsumerPortfolioSegmentMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember |  | 881 us-gaap_AllowanceForLoanAndLeaseLossRecoveryOfBadDebts / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_ConsumerPortfolioSegmentMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember | 111 us-gaap_AllowanceForLoanAndLeaseLossRecoveryOfBadDebts / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_ConsumerPortfolioSegmentMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember
Net (charge-offs) recoveries | (5,344)us-gaap_AllowanceForLoanAndLeaseLossesWriteoffsNet / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_ConsumerPortfolioSegmentMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember |  | (1,504)us-gaap_AllowanceForLoanAndLeaseLossesWriteoffsNet / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_ConsumerPortfolioSegmentMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember | (1,713)us-gaap_AllowanceForLoanAndLeaseLossesWriteoffsNet / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_ConsumerPortfolioSegmentMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember
Ending balance | 10,248 us-gaap_FinancingReceivableAllowanceForCreditLosses / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_ConsumerPortfolioSegmentMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember |  | 11,352 us-gaap_FinancingReceivableAllowanceForCreditLosses / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_ConsumerPortfolioSegmentMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember | 4,801 us-gaap_FinancingReceivableAllowanceForCreditLosses / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_ConsumerPortfolioSegmentMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember
Ending balance allocated to: |  |  |  |
Loans individually evaluated for impairment | 1 us-gaap_FinancingReceivableAllowanceForCreditLossesIndividuallyEvaluatedForImpairment1 / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_ConsumerPortfolioSegmentMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember |  |  |
Loans collectively evaluated for impairment | 10,247 us-gaap_FinancingReceivableAllowanceForCreditLossesCollectivelyEvaluatedForImpairment / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_ConsumerPortfolioSegmentMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember |  | 11,352 us-gaap_FinancingReceivableAllowanceForCreditLossesCollectivelyEvaluatedForImpairment / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_ConsumerPortfolioSegmentMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember | 4,801 us-gaap_FinancingReceivableAllowanceForCreditLossesCollectivelyEvaluatedForImpairment / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_ConsumerPortfolioSegmentMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember
Ending balance | 10,248 us-gaap_FinancingReceivableAllowanceForCreditLosses / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_ConsumerPortfolioSegmentMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember |  | 11,352 us-gaap_FinancingReceivableAllowanceForCreditLosses / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_ConsumerPortfolioSegmentMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember | 4,801 us-gaap_FinancingReceivableAllowanceForCreditLosses / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_ConsumerPortfolioSegmentMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember
Unallocated | Non-covered loans |  |  |  |
Financing Receivable Allowance for Credit Losses Roll Forward |  |  |  |
Allowance for unfunded loan commitments and letters of credit | (1,575)ewbc_FinancingReceivableAllowanceForCreditLossesAllowanceForUnfundedLoanCommitmentsAndLettersOfCredit / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_UnallocatedFinancingReceivablesMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember |  | (2,157)ewbc_FinancingReceivableAllowanceForCreditLossesAllowanceForUnfundedLoanCommitmentsAndLettersOfCredit / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_UnallocatedFinancingReceivablesMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember | 1,563 ewbc_FinancingReceivableAllowanceForCreditLossesAllowanceForUnfundedLoanCommitmentsAndLettersOfCredit / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_UnallocatedFinancingReceivablesMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember
Provision for (reversal of) loan losses | $ 1,575 us-gaap_ProvisionForLoanAndLeaseLosses / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_UnallocatedFinancingReceivablesMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember |  | $ 2,157 us-gaap_ProvisionForLoanAndLeaseLosses / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_UnallocatedFinancingReceivablesMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember | $ (1,563)us-gaap_ProvisionForLoanAndLeaseLosses / ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis = us-gaap_UnallocatedFinancingReceivablesMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_NonCoveredLoansMember
[1] | Includes a charge-off of $523 thousand related to PCI loans acquired from MetroCorp.

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- Definition Reflects the amount charged against earnings during the period as credit losses (bad debt expense) for unfunded loan commitments and letters of credit during the period. + References No definition available. + Details
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