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COVERED ASSETS AND FDIC INDEMNIFICATION ASSET (Details 6) (USD $) | 12 Months Ended | 0 Months Ended
--- | --- | ---
Dec. 31, 2014 | Dec. 31, 2013 | Dec. 31, 2012 | Nov. 06, 2009
Covered Nonperforming Assets |  |  |  |  |  |
Other real estate owned covered, net | $ 4,499,000 ewbc_OtherRealEstateOwnedCoveredNet |  | $ 21,373,000 ewbc_OtherRealEstateOwnedCoveredNet |  |  |
Number of past due days for the loans receivable to be placed on nonaccrual status | 90 days |  |  |  |  |
Covered assets - other disclosures |  |  |  |  |  |
Interest income related to loans removed | 87,500,000 ewbc_InterestIncomeRelatedToLoansRemoved |  | 168,100,000 ewbc_InterestIncomeRelatedToLoansRemoved |  |  |
Covered Loans |  |  |  |  |  |
Covered Nonperforming Assets |  |  |  |  |  |
Covered nonaccrual loans | 62,665,000 us-gaap_FinancingReceivableRecordedInvestmentNonaccrualStatus / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_CoveredLoansMember | [1],[2],[3] | 126,895,000 us-gaap_FinancingReceivableRecordedInvestmentNonaccrualStatus / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_CoveredLoansMember | [1],[2],[3] |  |
Other real estate owned covered, net | 4,499,000 ewbc_OtherRealEstateOwnedCoveredNet / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_CoveredLoansMember |  | 21,373,000 ewbc_OtherRealEstateOwnedCoveredNet / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_CoveredLoansMember |  |  |
Total covered nonperforming assets | 67,164,000 ewbc_TotalCoveredNonperformingAssets / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_CoveredLoansMember |  | 148,268,000 ewbc_TotalCoveredNonperformingAssets / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_CoveredLoansMember |  |  |
Percentage of any reimbursable expense recorded as interest income under ASC 310-30 | 80.00%ewbc_PercentageOfAnyReimbursableExpenseRecordedAsInterestIncome / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_CoveredLoansMember |  |  |  |  |
Covered loans past due 90 days or more but not on nonaccrual | 0 ewbc_CoveredLoansPastDue90DaysOrMoreButNotOnNonaccrual / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_CoveredLoansMember |  | 0 ewbc_CoveredLoansPastDue90DaysOrMoreButNotOnNonaccrual / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_CoveredLoansMember |  |  |
Number of past due days for the loans receivable to be placed on nonaccrual status | 90 days |  | 90 days |  |  |
Covered TDR activity |  |  |  |  |  |
Beginning balance | 116,007,000 ewbc_FinancingReceivableModificationsRecordedInvestmentCovered / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_CoveredLoansMember |  | 157,736,000 ewbc_FinancingReceivableModificationsRecordedInvestmentCovered / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_CoveredLoansMember |  |  |
Additions | 1,264,000 ewbc_FinancingReceivableModificationsRecordedInvestmentCoveredAdditions / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_CoveredLoansMember |  | 35,865,000 ewbc_FinancingReceivableModificationsRecordedInvestmentCoveredAdditions / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_CoveredLoansMember |  |  |
Transfers to covered OREO | (1,230,000)ewbc_FinancingReceivableModificationsRecordedInvestmentCoveredTransferredToOREO / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_CoveredLoansMember |  |  |  |  |
Charge-offs | (1,504,000)ewbc_FinancingReceivablesImpairedTroubledDebtRestructuringWriteDownCovered / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_CoveredLoansMember |  | (10,167,000)ewbc_FinancingReceivablesImpairedTroubledDebtRestructuringWriteDownCovered / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_CoveredLoansMember |  |  |
Paydowns/Reductions | (71,810,000)ewbc_FinancingReceivableModificationsRecordedInvestmentPaydownsOrReductions / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_CoveredLoansMember |  | (67,427,000)ewbc_FinancingReceivableModificationsRecordedInvestmentPaydownsOrReductions / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_CoveredLoansMember |  |  |
Ending Balance | 42,727,000 ewbc_FinancingReceivableModificationsRecordedInvestmentCovered / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_CoveredLoansMember |  | 116,007,000 ewbc_FinancingReceivableModificationsRecordedInvestmentCovered / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_CoveredLoansMember |  | 157,736,000 ewbc_FinancingReceivableModificationsRecordedInvestmentCovered / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_CoveredLoansMember |
Changes in the accretable yield for the covered loans |  |  |  |  |  |
Beginning balance | 461,545,000 us-gaap_CertainLoansAcquiredInTransferNotAccountedForAsDebtSecuritiesAccretableYield / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_CoveredLoansMember |  | 556,986,000 us-gaap_CertainLoansAcquiredInTransferNotAccountedForAsDebtSecuritiesAccretableYield / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_CoveredLoansMember |  | 785,165,000 us-gaap_CertainLoansAcquiredInTransferNotAccountedForAsDebtSecuritiesAccretableYield / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_CoveredLoansMember |
Accretion | (214,209,000)us-gaap_CertainLoansAcquiredInTransferNotAccountedForAsDebtSecuritiesAccretableYieldAccretion / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_CoveredLoansMember |  | (347,010,000)us-gaap_CertainLoansAcquiredInTransferNotAccountedForAsDebtSecuritiesAccretableYieldAccretion / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_CoveredLoansMember |  | (382,132,000)us-gaap_CertainLoansAcquiredInTransferNotAccountedForAsDebtSecuritiesAccretableYieldAccretion / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_CoveredLoansMember |
Changes in expected cash flows | 59,188,000 ewbc_ChangesInExpectedCashFlows / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_CoveredLoansMember |  | 251,569,000 ewbc_ChangesInExpectedCashFlows / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_CoveredLoansMember |  | 153,953,000 ewbc_ChangesInExpectedCashFlows / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_CoveredLoansMember |
Ending Balance | 306,524,000 us-gaap_CertainLoansAcquiredInTransferNotAccountedForAsDebtSecuritiesAccretableYield / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_CoveredLoansMember |  | 461,545,000 us-gaap_CertainLoansAcquiredInTransferNotAccountedForAsDebtSecuritiesAccretableYield / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_CoveredLoansMember |  | 556,986,000 us-gaap_CertainLoansAcquiredInTransferNotAccountedForAsDebtSecuritiesAccretableYield / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_CoveredLoansMember |
Covered assets - other disclosures |  |  |  |  |  |
Amount reclassified from nonaccretable yield to accretable yield due to changes in loss rate assumptions | 52,500,000 ewbc_CertainLoansAcquiredInTransferAccretableYieldReclassificationsFromNonaccretableDifference / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_CoveredLoansMember |  | 190,300,000 ewbc_CertainLoansAcquiredInTransferAccretableYieldReclassificationsFromNonaccretableDifference / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_CoveredLoansMember |  |  |
Amount of loans removed from the covered loans accounted for under ASC 310-30, excluding scheduled principal payments | 647,000,000 ewbc_AmountOfLoansRemovedFromCoveredLoans / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_CoveredLoansMember |  | 739,300,000 ewbc_AmountOfLoansRemovedFromCoveredLoans / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_CoveredLoansMember |  | 924,700,000 ewbc_AmountOfLoansRemovedFromCoveredLoans / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_CoveredLoansMember |
Interest income related to loans removed | 87,500,000 ewbc_InterestIncomeRelatedToLoansRemoved / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_CoveredLoansMember |  | 168,100,000 ewbc_InterestIncomeRelatedToLoansRemoved / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_CoveredLoansMember |  | 124,700,000 ewbc_InterestIncomeRelatedToLoansRemoved / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_CoveredLoansMember |
Covered Loans | Covered Advances |  |  |  |  |  |
Covered Nonperforming Assets |  |  |  |  |  |
Covered nonaccrual loans | 10,100,000 us-gaap_FinancingReceivableRecordedInvestmentNonaccrualStatus / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = ewbc_CoveredAdvancesMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_CoveredLoansMember |  | 17,700,000 us-gaap_FinancingReceivableRecordedInvestmentNonaccrualStatus / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = ewbc_CoveredAdvancesMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_CoveredLoansMember |  |  |
Covered Loans | PCI Covered Loans |  |  |  |  |  |
Covered Nonperforming Assets |  |  |  |  |  |
Covered nonaccrual loans | 52,600,000 us-gaap_FinancingReceivableRecordedInvestmentNonaccrualStatus / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = ewbc_PurchasedCreditImpairedCoveredLoansMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_CoveredLoansMember |  | 109,200,000 us-gaap_FinancingReceivableRecordedInvestmentNonaccrualStatus / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = ewbc_PurchasedCreditImpairedCoveredLoansMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_CoveredLoansMember |  |  |
Covered Loans | Covered OREO Properties |  |  |  |  |  |
Covered Nonperforming Assets |  |  |  |  |  |
Covered OREO balances | 4,500,000 ewbc_AggregateCarryingValueOfCoveredOreoProperties / us-gaap_ConcentrationRiskByBenchmarkAxis = ewbc_CoveredOtherRealEstateOwnedPropertiesMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_CoveredLoansMember |  |  |  |  |
Number of covered OREO properties added during the period | 17 ewbc_NumberOfCoveredOreoPropertiesAdded / us-gaap_ConcentrationRiskByBenchmarkAxis = ewbc_CoveredOtherRealEstateOwnedPropertiesMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_CoveredLoansMember |  |  |  |  |
Aggregate carrying value of covered OREO properties added during the period | 28,000,000 ewbc_AggregateCarryingValueOfCoveredOreoPropertiesAdded / us-gaap_ConcentrationRiskByBenchmarkAxis = ewbc_CoveredOtherRealEstateOwnedPropertiesMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_CoveredLoansMember |  | 21,400,000 ewbc_AggregateCarryingValueOfCoveredOreoPropertiesAdded / us-gaap_ConcentrationRiskByBenchmarkAxis = ewbc_CoveredOtherRealEstateOwnedPropertiesMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_CoveredLoansMember |  |  |
Net valuation adjustments included in aggregate carrying value on covered OREO properties | 1,300,000 ewbc_OtherRealEstateOwnedCoveredReductionsDueToAdjustments / us-gaap_ConcentrationRiskByBenchmarkAxis = ewbc_CoveredOtherRealEstateOwnedPropertiesMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_CoveredLoansMember |  | 2,400,000 ewbc_OtherRealEstateOwnedCoveredReductionsDueToAdjustments / us-gaap_ConcentrationRiskByBenchmarkAxis = ewbc_CoveredOtherRealEstateOwnedPropertiesMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_CoveredLoansMember |  |  |
Number of covered OREO properties sold during the period | 29 ewbc_NumberOfCoveredOreoPropertiesSold / us-gaap_ConcentrationRiskByBenchmarkAxis = ewbc_CoveredOtherRealEstateOwnedPropertiesMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_CoveredLoansMember |  |  |  |  |
Total proceeds value of covered OREO properties sold during the period | 52,100,000 ewbc_TotalProceedsOfCoveredOreoPropertiesSold / us-gaap_ConcentrationRiskByBenchmarkAxis = ewbc_CoveredOtherRealEstateOwnedPropertiesMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_CoveredLoansMember |  |  |  |  |
Total net gains (losses) on covered OREO properties sold during the period | $ 8,500,000 ewbc_CombinedNetGainsLossesOnCoveredOreoPropertiesSold / us-gaap_ConcentrationRiskByBenchmarkAxis = ewbc_CoveredOtherRealEstateOwnedPropertiesMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_CoveredLoansMember |  |  |  |  |
Covered Loans | United Commercial Bank (UCB) |  |  |  |  |  |
Credit Risk and Concentrations |  |  |  |  |  |
Percentage of the entity's total covered loans acquired from a specific counterparty | 93.00%ewbc_PercentageOfTotalCoveredLoansAcquiredFromCounterparty / us-gaap_BusinessAcquisitionAxis = ewbc_UnitedCommercialBankMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_CoveredLoansMember |  |  |  |  |
Number of general geographic regions | 3 ewbc_ConcentrationRiskNumberOfGeneralGeographicRegions / us-gaap_BusinessAcquisitionAxis = ewbc_UnitedCommercialBankMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_CoveredLoansMember |  |  |  |  |
Covered Loans | United Commercial Bank (UCB) | Covered loans acquired from specific acquiree | Geographic Concentration | California | PCI Covered Loans |  |  |  |  |  |
Credit Risk and Concentrations |  |  |  |  |  |
Percent of total |  |  |  |  |  | 64.00%us-gaap_ConcentrationRiskPercentage1 / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = ewbc_PurchasedCreditImpairedCoveredLoansMember / us-gaap_BusinessAcquisitionAxis = ewbc_UnitedCommercialBankMember / us-gaap_ConcentrationRiskByBenchmarkAxis = ewbc_CoveredLoansAcquiredFromSpecificAcquireeMember / us-gaap_ConcentrationRiskByTypeAxis = us-gaap_GeographicConcentrationRiskMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_CoveredLoansMember / ewbc_StatesAndProvincesAxis = stpr_CA
Covered Loans | United Commercial Bank (UCB) | Covered loans acquired from specific acquiree | Geographic Concentration | New York | PCI Covered Loans |  |  |  |  |  |
Credit Risk and Concentrations |  |  |  |  |  |
Percent of total |  |  |  |  |  | 11.00%us-gaap_ConcentrationRiskPercentage1 / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = ewbc_PurchasedCreditImpairedCoveredLoansMember / us-gaap_BusinessAcquisitionAxis = ewbc_UnitedCommercialBankMember / us-gaap_ConcentrationRiskByBenchmarkAxis = ewbc_CoveredLoansAcquiredFromSpecificAcquireeMember / us-gaap_ConcentrationRiskByTypeAxis = us-gaap_GeographicConcentrationRiskMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_CoveredLoansMember / ewbc_StatesAndProvincesAxis = stpr_NY
Covered Loans | United Commercial Bank (UCB) | Covered loans acquired from specific acquiree | Geographic Concentration | Hong Kong | PCI Covered Loans |  |  |  |  |  |
Credit Risk and Concentrations |  |  |  |  |  |
Percent of total |  |  |  |  |  | 10.00%us-gaap_ConcentrationRiskPercentage1 / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = ewbc_PurchasedCreditImpairedCoveredLoansMember / us-gaap_BusinessAcquisitionAxis = ewbc_UnitedCommercialBankMember / us-gaap_ConcentrationRiskByBenchmarkAxis = ewbc_CoveredLoansAcquiredFromSpecificAcquireeMember / us-gaap_ConcentrationRiskByTypeAxis = us-gaap_GeographicConcentrationRiskMember / ewbc_ReceivableByIndemnificationStatusAxis = ewbc_CoveredLoansMember / us-gaap_StatementGeographicalAxis = country_HK
[1] | Covered nonaccrual loans include loans that meet the criteria for nonaccrual but have a yield accreted through interest income under ASC 310-30.All losses on covered loans are 80% reimbursed by the FDIC.
[2] | Net of discount.
[3] | Includes $10.1 million and $17.7 million of covered advances as of December 31, 2014 and December 31, 2013, respectively; and $52.6 million and $109.2 million of PCI loans as of December 31, 2014 and December 31, 2013, respectively.

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- Definition Aggregate carrying value of OREO properties covered by shared-loss agreements that were added during the period. + References No definition available. + Details
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- Definition Represents the change in the estimate of cash flows expected to be collected. This relates to a loan accounted for as an available-for-sale debt security, with evidence of deterioration of credit quality since origination that was acquired by completion of a transfer for which it is probable, at acquisition, that the investor will be unable to collect all contractually required payments receivable. + References No definition available. + Details
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- Definition The carrying amount as of the balance sheet date of covered loans receivable that are considered to be nonperforming assets and are past due 90 days or more, but are not on nonaccrual status. + References No definition available. + Details
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