XML 60 R65.htm IDEA: XBRL DOCUMENT v2.4.1.9
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES (Details 6) (Non-PCI loans, Loans Receivable, USD $)
In Thousands, unless otherwise specified
 3 Months Ended
Mar. 31, 2015
Mar. 31, 2014
Dec. 31, 2014
Impaired loans disclosures      
Unpaid principal balance $ 150,338us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance   $ 177,381us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance
Recorded Investment With No Allowance 71,100us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceRecordedInvestment   82,465us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceRecordedInvestment
Recorded Investment With Allowance 59,052us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceRecordedInvestment   71,655us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceRecordedInvestment
Recorded investment 130,152us-gaap_ImpairedFinancingReceivableRecordedInvestment   154,120us-gaap_ImpairedFinancingReceivableRecordedInvestment
Related allowance 20,173us-gaap_ImpairedFinancingReceivableRelatedAllowance   19,464us-gaap_ImpairedFinancingReceivableRelatedAllowance
Average recorded investment 134,758us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment 186,935us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment  
Interest income recognized (accrual basis) 639us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod [1] 913us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod [1]  
CRE | Income producing      
Impaired loans disclosures      
Unpaid principal balance 50,389us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= us-gaap_LoansReceivableMember
/ us-gaap_FairValueByAssetClassAxis
= ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember
/ ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= ewbc_IncomeProducingFinancingReceivableMember		   57,805us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= us-gaap_LoansReceivableMember
/ us-gaap_FairValueByAssetClassAxis
= ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember
/ ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= ewbc_IncomeProducingFinancingReceivableMember
Recorded Investment With No Allowance 28,186us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceRecordedInvestment
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= us-gaap_LoansReceivableMember
/ us-gaap_FairValueByAssetClassAxis
= ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember
/ ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= ewbc_IncomeProducingFinancingReceivableMember		   34,399us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceRecordedInvestment
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= us-gaap_LoansReceivableMember
/ us-gaap_FairValueByAssetClassAxis
= ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember
/ ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= ewbc_IncomeProducingFinancingReceivableMember
Recorded Investment With Allowance 15,001us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceRecordedInvestment
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= us-gaap_LoansReceivableMember
/ us-gaap_FairValueByAssetClassAxis
= ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember
/ ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= ewbc_IncomeProducingFinancingReceivableMember		   15,646us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceRecordedInvestment
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= us-gaap_LoansReceivableMember
/ us-gaap_FairValueByAssetClassAxis
= ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember
/ ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= ewbc_IncomeProducingFinancingReceivableMember
Recorded investment 43,187us-gaap_ImpairedFinancingReceivableRecordedInvestment
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= us-gaap_LoansReceivableMember
/ us-gaap_FairValueByAssetClassAxis
= ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember
/ ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= ewbc_IncomeProducingFinancingReceivableMember		   50,045us-gaap_ImpairedFinancingReceivableRecordedInvestment
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= us-gaap_LoansReceivableMember
/ us-gaap_FairValueByAssetClassAxis
= ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember
/ ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= ewbc_IncomeProducingFinancingReceivableMember
Related allowance 1,399us-gaap_ImpairedFinancingReceivableRelatedAllowance
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= us-gaap_LoansReceivableMember
/ us-gaap_FairValueByAssetClassAxis
= ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember
/ ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= ewbc_IncomeProducingFinancingReceivableMember		   1,581us-gaap_ImpairedFinancingReceivableRelatedAllowance
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= us-gaap_LoansReceivableMember
/ us-gaap_FairValueByAssetClassAxis
= ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember
/ ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= ewbc_IncomeProducingFinancingReceivableMember
Average recorded investment 44,195us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= us-gaap_LoansReceivableMember
/ us-gaap_FairValueByAssetClassAxis
= ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember
/ ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= ewbc_IncomeProducingFinancingReceivableMember		 67,153us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= us-gaap_LoansReceivableMember
/ us-gaap_FairValueByAssetClassAxis
= ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember
/ ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= ewbc_IncomeProducingFinancingReceivableMember		  
Interest income recognized (accrual basis) 141us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= us-gaap_LoansReceivableMember
/ us-gaap_FairValueByAssetClassAxis
= ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember
/ ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= ewbc_IncomeProducingFinancingReceivableMember		 [1] 325us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= us-gaap_LoansReceivableMember
/ us-gaap_FairValueByAssetClassAxis
= ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember
/ ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= ewbc_IncomeProducingFinancingReceivableMember		 [1]  
CRE | Construction      
Impaired loans disclosures      
Unpaid principal balance 916us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= us-gaap_LoansReceivableMember
/ us-gaap_FairValueByAssetClassAxis
= ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember
/ ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstateConstructionFinancingReceivableMember		   6,888us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= us-gaap_LoansReceivableMember
/ us-gaap_FairValueByAssetClassAxis
= ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember
/ ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstateConstructionFinancingReceivableMember
Recorded Investment With No Allowance 916us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceRecordedInvestment
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= us-gaap_LoansReceivableMember
/ us-gaap_FairValueByAssetClassAxis
= ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember
/ ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstateConstructionFinancingReceivableMember		   6,888us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceRecordedInvestment
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= us-gaap_LoansReceivableMember
/ us-gaap_FairValueByAssetClassAxis
= ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember
/ ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstateConstructionFinancingReceivableMember
Recorded investment 916us-gaap_ImpairedFinancingReceivableRecordedInvestment
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= us-gaap_LoansReceivableMember
/ us-gaap_FairValueByAssetClassAxis
= ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember
/ ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstateConstructionFinancingReceivableMember		   6,888us-gaap_ImpairedFinancingReceivableRecordedInvestment
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= us-gaap_LoansReceivableMember
/ us-gaap_FairValueByAssetClassAxis
= ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember
/ ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstateConstructionFinancingReceivableMember
Average recorded investment 3,902us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= us-gaap_LoansReceivableMember
/ us-gaap_FairValueByAssetClassAxis
= ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember
/ ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstateConstructionFinancingReceivableMember		 6,888us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= us-gaap_LoansReceivableMember
/ us-gaap_FairValueByAssetClassAxis
= ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember
/ ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstateConstructionFinancingReceivableMember		  
CRE | Land      
Impaired loans disclosures      
Unpaid principal balance 8,234us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= us-gaap_LoansReceivableMember
/ us-gaap_FairValueByAssetClassAxis
= ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember
/ ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= ewbc_LandCommercialRealEstateMember		   13,291us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= us-gaap_LoansReceivableMember
/ us-gaap_FairValueByAssetClassAxis
= ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember
/ ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= ewbc_LandCommercialRealEstateMember
Recorded Investment With No Allowance 2,826us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceRecordedInvestment
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= us-gaap_LoansReceivableMember
/ us-gaap_FairValueByAssetClassAxis
= ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember
/ ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= ewbc_LandCommercialRealEstateMember		   2,838us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceRecordedInvestment
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= us-gaap_LoansReceivableMember
/ us-gaap_FairValueByAssetClassAxis
= ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember
/ ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= ewbc_LandCommercialRealEstateMember
Recorded Investment With Allowance 543us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceRecordedInvestment
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= us-gaap_LoansReceivableMember
/ us-gaap_FairValueByAssetClassAxis
= ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember
/ ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= ewbc_LandCommercialRealEstateMember		   5,622us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceRecordedInvestment
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= us-gaap_LoansReceivableMember
/ us-gaap_FairValueByAssetClassAxis
= ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember
/ ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= ewbc_LandCommercialRealEstateMember
Recorded investment 3,369us-gaap_ImpairedFinancingReceivableRecordedInvestment
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= us-gaap_LoansReceivableMember
/ us-gaap_FairValueByAssetClassAxis
= ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember
/ ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= ewbc_LandCommercialRealEstateMember		   8,460us-gaap_ImpairedFinancingReceivableRecordedInvestment
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= us-gaap_LoansReceivableMember
/ us-gaap_FairValueByAssetClassAxis
= ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember
/ ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= ewbc_LandCommercialRealEstateMember
Related allowance 175us-gaap_ImpairedFinancingReceivableRelatedAllowance
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= us-gaap_LoansReceivableMember
/ us-gaap_FairValueByAssetClassAxis
= ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember
/ ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= ewbc_LandCommercialRealEstateMember		   1,906us-gaap_ImpairedFinancingReceivableRelatedAllowance
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= us-gaap_LoansReceivableMember
/ us-gaap_FairValueByAssetClassAxis
= ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember
/ ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= ewbc_LandCommercialRealEstateMember
Average recorded investment 3,438us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= us-gaap_LoansReceivableMember
/ us-gaap_FairValueByAssetClassAxis
= ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember
/ ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= ewbc_LandCommercialRealEstateMember		 12,227us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= us-gaap_LoansReceivableMember
/ us-gaap_FairValueByAssetClassAxis
= ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember
/ ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= ewbc_LandCommercialRealEstateMember		  
Interest income recognized (accrual basis) 10us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= us-gaap_LoansReceivableMember
/ us-gaap_FairValueByAssetClassAxis
= ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember
/ ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= ewbc_LandCommercialRealEstateMember		 [1] 121us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= us-gaap_LoansReceivableMember
/ us-gaap_FairValueByAssetClassAxis
= ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember
/ ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= ewbc_LandCommercialRealEstateMember		 [1]  
C&I | Commercial business      
Impaired loans disclosures      
Unpaid principal balance 43,289us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= us-gaap_LoansReceivableMember
/ us-gaap_FairValueByAssetClassAxis
= ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember
/ ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis
= us-gaap_CommercialPortfolioSegmentMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= ewbc_CommercialBusinessMember		   42,396us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= us-gaap_LoansReceivableMember
/ us-gaap_FairValueByAssetClassAxis
= ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember
/ ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis
= us-gaap_CommercialPortfolioSegmentMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= ewbc_CommercialBusinessMember
Recorded Investment With No Allowance 10,815us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceRecordedInvestment
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= us-gaap_LoansReceivableMember
/ us-gaap_FairValueByAssetClassAxis
= ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember
/ ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis
= us-gaap_CommercialPortfolioSegmentMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= ewbc_CommercialBusinessMember		   10,552us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceRecordedInvestment
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= us-gaap_LoansReceivableMember
/ us-gaap_FairValueByAssetClassAxis
= ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember
/ ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis
= us-gaap_CommercialPortfolioSegmentMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= ewbc_CommercialBusinessMember
Recorded Investment With Allowance 28,186us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceRecordedInvestment
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= us-gaap_LoansReceivableMember
/ us-gaap_FairValueByAssetClassAxis
= ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember
/ ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis
= us-gaap_CommercialPortfolioSegmentMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= ewbc_CommercialBusinessMember		   25,717us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceRecordedInvestment
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= us-gaap_LoansReceivableMember
/ us-gaap_FairValueByAssetClassAxis
= ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember
/ ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis
= us-gaap_CommercialPortfolioSegmentMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= ewbc_CommercialBusinessMember
Recorded investment 39,001us-gaap_ImpairedFinancingReceivableRecordedInvestment
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= us-gaap_LoansReceivableMember
/ us-gaap_FairValueByAssetClassAxis
= ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember
/ ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis
= us-gaap_CommercialPortfolioSegmentMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= ewbc_CommercialBusinessMember		   36,269us-gaap_ImpairedFinancingReceivableRecordedInvestment
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= us-gaap_LoansReceivableMember
/ us-gaap_FairValueByAssetClassAxis
= ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember
/ ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis
= us-gaap_CommercialPortfolioSegmentMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= ewbc_CommercialBusinessMember
Related allowance 17,886us-gaap_ImpairedFinancingReceivableRelatedAllowance
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= us-gaap_LoansReceivableMember
/ us-gaap_FairValueByAssetClassAxis
= ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember
/ ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis
= us-gaap_CommercialPortfolioSegmentMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= ewbc_CommercialBusinessMember		   15,174us-gaap_ImpairedFinancingReceivableRelatedAllowance
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= us-gaap_LoansReceivableMember
/ us-gaap_FairValueByAssetClassAxis
= ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember
/ ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis
= us-gaap_CommercialPortfolioSegmentMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= ewbc_CommercialBusinessMember
Average recorded investment 39,310us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= us-gaap_LoansReceivableMember
/ us-gaap_FairValueByAssetClassAxis
= ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember
/ ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis
= us-gaap_CommercialPortfolioSegmentMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= ewbc_CommercialBusinessMember		 43,726us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= us-gaap_LoansReceivableMember
/ us-gaap_FairValueByAssetClassAxis
= ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember
/ ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis
= us-gaap_CommercialPortfolioSegmentMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= ewbc_CommercialBusinessMember		  
Interest income recognized (accrual basis) 202us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= us-gaap_LoansReceivableMember
/ us-gaap_FairValueByAssetClassAxis
= ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember
/ ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis
= us-gaap_CommercialPortfolioSegmentMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= ewbc_CommercialBusinessMember		 [1] 207us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= us-gaap_LoansReceivableMember
/ us-gaap_FairValueByAssetClassAxis
= ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember
/ ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis
= us-gaap_CommercialPortfolioSegmentMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= ewbc_CommercialBusinessMember		 [1]  
C&I | Trade finance      
Impaired loans disclosures      
Unpaid principal balance 223us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= us-gaap_LoansReceivableMember
/ us-gaap_FairValueByAssetClassAxis
= ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember
/ ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis
= us-gaap_CommercialPortfolioSegmentMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= ewbc_TradeFinanceMember		   280us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= us-gaap_LoansReceivableMember
/ us-gaap_FairValueByAssetClassAxis
= ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember
/ ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis
= us-gaap_CommercialPortfolioSegmentMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= ewbc_TradeFinanceMember
Recorded Investment With Allowance 216us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceRecordedInvestment
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= us-gaap_LoansReceivableMember
/ us-gaap_FairValueByAssetClassAxis
= ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember
/ ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis
= us-gaap_CommercialPortfolioSegmentMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= ewbc_TradeFinanceMember		   274us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceRecordedInvestment
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= us-gaap_LoansReceivableMember
/ us-gaap_FairValueByAssetClassAxis
= ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember
/ ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis
= us-gaap_CommercialPortfolioSegmentMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= ewbc_TradeFinanceMember
Recorded investment 216us-gaap_ImpairedFinancingReceivableRecordedInvestment
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= us-gaap_LoansReceivableMember
/ us-gaap_FairValueByAssetClassAxis
= ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember
/ ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis
= us-gaap_CommercialPortfolioSegmentMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= ewbc_TradeFinanceMember		   274us-gaap_ImpairedFinancingReceivableRecordedInvestment
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= us-gaap_LoansReceivableMember
/ us-gaap_FairValueByAssetClassAxis
= ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember
/ ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis
= us-gaap_CommercialPortfolioSegmentMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= ewbc_TradeFinanceMember
Related allowance 20us-gaap_ImpairedFinancingReceivableRelatedAllowance
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= us-gaap_LoansReceivableMember
/ us-gaap_FairValueByAssetClassAxis
= ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember
/ ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis
= us-gaap_CommercialPortfolioSegmentMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= ewbc_TradeFinanceMember		   28us-gaap_ImpairedFinancingReceivableRelatedAllowance
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= us-gaap_LoansReceivableMember
/ us-gaap_FairValueByAssetClassAxis
= ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember
/ ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis
= us-gaap_CommercialPortfolioSegmentMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= ewbc_TradeFinanceMember
Average recorded investment 245us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= us-gaap_LoansReceivableMember
/ us-gaap_FairValueByAssetClassAxis
= ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember
/ ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis
= us-gaap_CommercialPortfolioSegmentMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= ewbc_TradeFinanceMember		 637us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= us-gaap_LoansReceivableMember
/ us-gaap_FairValueByAssetClassAxis
= ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember
/ ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis
= us-gaap_CommercialPortfolioSegmentMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= ewbc_TradeFinanceMember		  
Interest income recognized (accrual basis) 3us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= us-gaap_LoansReceivableMember
/ us-gaap_FairValueByAssetClassAxis
= ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember
/ ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis
= us-gaap_CommercialPortfolioSegmentMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= ewbc_TradeFinanceMember		 [1] 4us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= us-gaap_LoansReceivableMember
/ us-gaap_FairValueByAssetClassAxis
= ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember
/ ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis
= us-gaap_CommercialPortfolioSegmentMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= ewbc_TradeFinanceMember		 [1]  
Residential | Single-family      
Impaired loans disclosures      
Unpaid principal balance 16,767us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= us-gaap_LoansReceivableMember
/ us-gaap_FairValueByAssetClassAxis
= ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember
/ ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis
= us-gaap_ResidentialPortfolioSegmentMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= ewbc_ResidentialSingleFamilyMember		   17,838us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= us-gaap_LoansReceivableMember
/ us-gaap_FairValueByAssetClassAxis
= ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember
/ ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis
= us-gaap_ResidentialPortfolioSegmentMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= ewbc_ResidentialSingleFamilyMember
Recorded Investment With No Allowance 7,007us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceRecordedInvestment
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= us-gaap_LoansReceivableMember
/ us-gaap_FairValueByAssetClassAxis
= ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember
/ ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis
= us-gaap_ResidentialPortfolioSegmentMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= ewbc_ResidentialSingleFamilyMember		   5,137us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceRecordedInvestment
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= us-gaap_LoansReceivableMember
/ us-gaap_FairValueByAssetClassAxis
= ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember
/ ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis
= us-gaap_ResidentialPortfolioSegmentMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= ewbc_ResidentialSingleFamilyMember
Recorded Investment With Allowance 8,404us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceRecordedInvestment
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= us-gaap_LoansReceivableMember
/ us-gaap_FairValueByAssetClassAxis
= ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember
/ ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis
= us-gaap_ResidentialPortfolioSegmentMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= ewbc_ResidentialSingleFamilyMember		   11,398us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceRecordedInvestment
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= us-gaap_LoansReceivableMember
/ us-gaap_FairValueByAssetClassAxis
= ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember
/ ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis
= us-gaap_ResidentialPortfolioSegmentMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= ewbc_ResidentialSingleFamilyMember
Recorded investment 15,411us-gaap_ImpairedFinancingReceivableRecordedInvestment
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= us-gaap_LoansReceivableMember
/ us-gaap_FairValueByAssetClassAxis
= ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember
/ ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis
= us-gaap_ResidentialPortfolioSegmentMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= ewbc_ResidentialSingleFamilyMember		   16,535us-gaap_ImpairedFinancingReceivableRecordedInvestment
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= us-gaap_LoansReceivableMember
/ us-gaap_FairValueByAssetClassAxis
= ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember
/ ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis
= us-gaap_ResidentialPortfolioSegmentMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= ewbc_ResidentialSingleFamilyMember
Related allowance 413us-gaap_ImpairedFinancingReceivableRelatedAllowance
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= us-gaap_LoansReceivableMember
/ us-gaap_FairValueByAssetClassAxis
= ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember
/ ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis
= us-gaap_ResidentialPortfolioSegmentMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= ewbc_ResidentialSingleFamilyMember		   461us-gaap_ImpairedFinancingReceivableRelatedAllowance
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= us-gaap_LoansReceivableMember
/ us-gaap_FairValueByAssetClassAxis
= ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember
/ ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis
= us-gaap_ResidentialPortfolioSegmentMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= ewbc_ResidentialSingleFamilyMember
Average recorded investment 15,423us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= us-gaap_LoansReceivableMember
/ us-gaap_FairValueByAssetClassAxis
= ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember
/ ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis
= us-gaap_ResidentialPortfolioSegmentMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= ewbc_ResidentialSingleFamilyMember		 17,100us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= us-gaap_LoansReceivableMember
/ us-gaap_FairValueByAssetClassAxis
= ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember
/ ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis
= us-gaap_ResidentialPortfolioSegmentMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= ewbc_ResidentialSingleFamilyMember		  
Interest income recognized (accrual basis) 68us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= us-gaap_LoansReceivableMember
/ us-gaap_FairValueByAssetClassAxis
= ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember
/ ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis
= us-gaap_ResidentialPortfolioSegmentMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= ewbc_ResidentialSingleFamilyMember		 [1] 50us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= us-gaap_LoansReceivableMember
/ us-gaap_FairValueByAssetClassAxis
= ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember
/ ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis
= us-gaap_ResidentialPortfolioSegmentMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= ewbc_ResidentialSingleFamilyMember		 [1]  
Residential | Multifamily      
Impaired loans disclosures      
Unpaid principal balance 29,262us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= us-gaap_LoansReceivableMember
/ us-gaap_FairValueByAssetClassAxis
= ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember
/ ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis
= us-gaap_ResidentialPortfolioSegmentMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= ewbc_ResidentialMultifamilyMember		   37,624us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= us-gaap_LoansReceivableMember
/ us-gaap_FairValueByAssetClassAxis
= ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember
/ ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis
= us-gaap_ResidentialPortfolioSegmentMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= ewbc_ResidentialMultifamilyMember
Recorded Investment With No Allowance 20,200us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceRecordedInvestment
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= us-gaap_LoansReceivableMember
/ us-gaap_FairValueByAssetClassAxis
= ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember
/ ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis
= us-gaap_ResidentialPortfolioSegmentMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= ewbc_ResidentialMultifamilyMember		   21,500us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceRecordedInvestment
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= us-gaap_LoansReceivableMember
/ us-gaap_FairValueByAssetClassAxis
= ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember
/ ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis
= us-gaap_ResidentialPortfolioSegmentMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= ewbc_ResidentialMultifamilyMember
Recorded Investment With Allowance 6,594us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceRecordedInvestment
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= us-gaap_LoansReceivableMember
/ us-gaap_FairValueByAssetClassAxis
= ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember
/ ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis
= us-gaap_ResidentialPortfolioSegmentMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= ewbc_ResidentialMultifamilyMember		   12,890us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceRecordedInvestment
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= us-gaap_LoansReceivableMember
/ us-gaap_FairValueByAssetClassAxis
= ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember
/ ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis
= us-gaap_ResidentialPortfolioSegmentMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= ewbc_ResidentialMultifamilyMember
Recorded investment 26,794us-gaap_ImpairedFinancingReceivableRecordedInvestment
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= us-gaap_LoansReceivableMember
/ us-gaap_FairValueByAssetClassAxis
= ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember
/ ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis
= us-gaap_ResidentialPortfolioSegmentMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= ewbc_ResidentialMultifamilyMember		   34,390us-gaap_ImpairedFinancingReceivableRecordedInvestment
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= us-gaap_LoansReceivableMember
/ us-gaap_FairValueByAssetClassAxis
= ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember
/ ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis
= us-gaap_ResidentialPortfolioSegmentMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= ewbc_ResidentialMultifamilyMember
Related allowance 279us-gaap_ImpairedFinancingReceivableRelatedAllowance
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= us-gaap_LoansReceivableMember
/ us-gaap_FairValueByAssetClassAxis
= ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember
/ ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis
= us-gaap_ResidentialPortfolioSegmentMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= ewbc_ResidentialMultifamilyMember		   313us-gaap_ImpairedFinancingReceivableRelatedAllowance
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= us-gaap_LoansReceivableMember
/ us-gaap_FairValueByAssetClassAxis
= ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember
/ ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis
= us-gaap_ResidentialPortfolioSegmentMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= ewbc_ResidentialMultifamilyMember
Average recorded investment 26,987us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= us-gaap_LoansReceivableMember
/ us-gaap_FairValueByAssetClassAxis
= ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember
/ ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis
= us-gaap_ResidentialPortfolioSegmentMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= ewbc_ResidentialMultifamilyMember		 36,369us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= us-gaap_LoansReceivableMember
/ us-gaap_FairValueByAssetClassAxis
= ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember
/ ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis
= us-gaap_ResidentialPortfolioSegmentMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= ewbc_ResidentialMultifamilyMember		  
Interest income recognized (accrual basis) 203us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= us-gaap_LoansReceivableMember
/ us-gaap_FairValueByAssetClassAxis
= ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember
/ ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis
= us-gaap_ResidentialPortfolioSegmentMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= ewbc_ResidentialMultifamilyMember		 [1] 205us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= us-gaap_LoansReceivableMember
/ us-gaap_FairValueByAssetClassAxis
= ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember
/ ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis
= us-gaap_ResidentialPortfolioSegmentMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= ewbc_ResidentialMultifamilyMember		 [1]  
Consumer      
Impaired loans disclosures      
Unpaid principal balance 1,258us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= us-gaap_LoansReceivableMember
/ us-gaap_FairValueByAssetClassAxis
= ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember
/ ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis
= us-gaap_ConsumerPortfolioSegmentMember		   1,259us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= us-gaap_LoansReceivableMember
/ us-gaap_FairValueByAssetClassAxis
= ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember
/ ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis
= us-gaap_ConsumerPortfolioSegmentMember
Recorded Investment With No Allowance 1,150us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceRecordedInvestment
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= us-gaap_LoansReceivableMember
/ us-gaap_FairValueByAssetClassAxis
= ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember
/ ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis
= us-gaap_ConsumerPortfolioSegmentMember		   1,151us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceRecordedInvestment
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= us-gaap_LoansReceivableMember
/ us-gaap_FairValueByAssetClassAxis
= ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember
/ ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis
= us-gaap_ConsumerPortfolioSegmentMember
Recorded Investment With Allowance 108us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceRecordedInvestment
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= us-gaap_LoansReceivableMember
/ us-gaap_FairValueByAssetClassAxis
= ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember
/ ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis
= us-gaap_ConsumerPortfolioSegmentMember		   108us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceRecordedInvestment
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= us-gaap_LoansReceivableMember
/ us-gaap_FairValueByAssetClassAxis
= ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember
/ ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis
= us-gaap_ConsumerPortfolioSegmentMember
Recorded investment 1,258us-gaap_ImpairedFinancingReceivableRecordedInvestment
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= us-gaap_LoansReceivableMember
/ us-gaap_FairValueByAssetClassAxis
= ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember
/ ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis
= us-gaap_ConsumerPortfolioSegmentMember		   1,259us-gaap_ImpairedFinancingReceivableRecordedInvestment
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= us-gaap_LoansReceivableMember
/ us-gaap_FairValueByAssetClassAxis
= ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember
/ ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis
= us-gaap_ConsumerPortfolioSegmentMember
Related allowance 1us-gaap_ImpairedFinancingReceivableRelatedAllowance
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= us-gaap_LoansReceivableMember
/ us-gaap_FairValueByAssetClassAxis
= ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember
/ ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis
= us-gaap_ConsumerPortfolioSegmentMember		   1us-gaap_ImpairedFinancingReceivableRelatedAllowance
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= us-gaap_LoansReceivableMember
/ us-gaap_FairValueByAssetClassAxis
= ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember
/ ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis
= us-gaap_ConsumerPortfolioSegmentMember
Average recorded investment 1,258us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= us-gaap_LoansReceivableMember
/ us-gaap_FairValueByAssetClassAxis
= ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember
/ ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis
= us-gaap_ConsumerPortfolioSegmentMember		 2,835us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= us-gaap_LoansReceivableMember
/ us-gaap_FairValueByAssetClassAxis
= ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember
/ ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis
= us-gaap_ConsumerPortfolioSegmentMember		  
Interest income recognized (accrual basis) $ 12us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= us-gaap_LoansReceivableMember
/ us-gaap_FairValueByAssetClassAxis
= ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember
/ ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis
= us-gaap_ConsumerPortfolioSegmentMember		 [1] $ 1us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod
/ us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis
= us-gaap_LoansReceivableMember
/ us-gaap_FairValueByAssetClassAxis
= ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember
/ ewbc_FinancingReceivableInformationByPortfolioSegmentsAxis
= us-gaap_ConsumerPortfolioSegmentMember		 [1]  
[1] Includes interest recognized on accruing non-PCI TDRs. Interest payments received on nonaccrual non-PCI loans are generally reflected as a reduction of principal and not as interest income.