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DERIVATIVE FINANCIAL INSTRUMENTS (Details 5) (USD $) | Mar. 31, 2015 | Dec. 31, 2014
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Counterparties assets |  |  |  |
Assets, Derivatives |  |  |  |
Gross Amounts of Recognized Assets | $ 13,564,000 us-gaap_DerivativeFairValueOfDerivativeAsset / us-gaap_CounterpartyNameAxis = ewbc_CounterpartiesAssetsMember |  | $ 12,396,000 us-gaap_DerivativeFairValueOfDerivativeAsset / us-gaap_CounterpartyNameAxis = ewbc_CounterpartiesAssetsMember |
Gross Amounts Offset On the Consolidated Balance Sheet | 0 us-gaap_DerivativeAssetFairValueGrossLiabilityAndObligationToReturnCashOffset / us-gaap_CounterpartyNameAxis = ewbc_CounterpartiesAssetsMember |  | 0 us-gaap_DerivativeAssetFairValueGrossLiabilityAndObligationToReturnCashOffset / us-gaap_CounterpartyNameAxis = ewbc_CounterpartiesAssetsMember |
Net Amounts of Assets Presented | 13,564,000 us-gaap_DerivativeAssets / us-gaap_CounterpartyNameAxis = ewbc_CounterpartiesAssetsMember |  | 12,396,000 us-gaap_DerivativeAssets / us-gaap_CounterpartyNameAxis = ewbc_CounterpartiesAssetsMember |
Gross Amounts Not Offset on the Consolidated Balance Sheet |  |  |  |
Financial Instruments | (6,002,000)us-gaap_DerivativeAssetNotOffsetPolicyElectionDeduction / us-gaap_CounterpartyNameAxis = ewbc_CounterpartiesAssetsMember | [1] | (5,725,000)us-gaap_DerivativeAssetNotOffsetPolicyElectionDeduction / us-gaap_CounterpartyNameAxis = ewbc_CounterpartiesAssetsMember | [1]
Collateral Received | (6,480,000)ewbc_DerivativeCollateralObligationToReturnCollateral / us-gaap_CounterpartyNameAxis = ewbc_CounterpartiesAssetsMember | [2] | (3,463,000)ewbc_DerivativeCollateralObligationToReturnCollateral / us-gaap_CounterpartyNameAxis = ewbc_CounterpartiesAssetsMember | [2]
Net Amount | 1,082,000 us-gaap_DerivativeFairValueOfDerivativeAssetAmountOffsetAgainstCollateral / us-gaap_CounterpartyNameAxis = ewbc_CounterpartiesAssetsMember |  | 3,208,000 us-gaap_DerivativeFairValueOfDerivativeAssetAmountOffsetAgainstCollateral / us-gaap_CounterpartyNameAxis = ewbc_CounterpartiesAssetsMember |
Cash collateral received | 6,500,000 us-gaap_DerivativeCollateralObligationToReturnCash / us-gaap_CounterpartyNameAxis = ewbc_CounterpartiesAssetsMember |  | 3,500,000 us-gaap_DerivativeCollateralObligationToReturnCash / us-gaap_CounterpartyNameAxis = ewbc_CounterpartiesAssetsMember |
Counterparties liabilities |  |  |  |
Liabilities, Derivatives |  |  |  |
Gross Amounts of Recognized Liabilities | 79,890,000 us-gaap_DerivativeFairValueOfDerivativeLiability / us-gaap_CounterpartyNameAxis = ewbc_CounterpartiesLiabilitiesMember |  | 56,505,000 us-gaap_DerivativeFairValueOfDerivativeLiability / us-gaap_CounterpartyNameAxis = ewbc_CounterpartiesLiabilitiesMember |
Gross Amounts Offset On the Consolidated Balance Sheet | 0 us-gaap_DerivativeLiabilityFairValueGrossAssetAndRightToReclaimCashOffset / us-gaap_CounterpartyNameAxis = ewbc_CounterpartiesLiabilitiesMember |  | 0 us-gaap_DerivativeLiabilityFairValueGrossAssetAndRightToReclaimCashOffset / us-gaap_CounterpartyNameAxis = ewbc_CounterpartiesLiabilitiesMember |
Net Amounts of Liabilities Presented | 79,890,000 us-gaap_DerivativeLiabilities / us-gaap_CounterpartyNameAxis = ewbc_CounterpartiesLiabilitiesMember |  | 56,505,000 us-gaap_DerivativeLiabilities / us-gaap_CounterpartyNameAxis = ewbc_CounterpartiesLiabilitiesMember |
Gross Amounts Not Offset on the Consolidated Balance Sheet |  |  |  |
Financial Instruments | (6,002,000)us-gaap_DerivativeLiabilityNotOffsetPolicyElectionDeduction / us-gaap_CounterpartyNameAxis = ewbc_CounterpartiesLiabilitiesMember | [1] | (5,725,000)us-gaap_DerivativeLiabilityNotOffsetPolicyElectionDeduction / us-gaap_CounterpartyNameAxis = ewbc_CounterpartiesLiabilitiesMember | [1]
Collateral Posted | (72,018,000)ewbc_DerivativeCollateralRightToReclaimCollateral / us-gaap_CounterpartyNameAxis = ewbc_CounterpartiesLiabilitiesMember | [3] | (49,951,000)ewbc_DerivativeCollateralRightToReclaimCollateral / us-gaap_CounterpartyNameAxis = ewbc_CounterpartiesLiabilitiesMember | [3]
Net Amount | 1,870,000 us-gaap_DerivativeFairValueOfDerivativeLiabilityAmountOffsetAgainstCollateral / us-gaap_CounterpartyNameAxis = ewbc_CounterpartiesLiabilitiesMember |  | 829,000 us-gaap_DerivativeFairValueOfDerivativeLiabilityAmountOffsetAgainstCollateral / us-gaap_CounterpartyNameAxis = ewbc_CounterpartiesLiabilitiesMember |
Cash collateral posted | $ 19,000,000 us-gaap_DerivativeCollateralRightToReclaimCash / us-gaap_CounterpartyNameAxis = ewbc_CounterpartiesLiabilitiesMember |  | $ 12,800,000 us-gaap_DerivativeCollateralRightToReclaimCash / us-gaap_CounterpartyNameAxis = ewbc_CounterpartiesLiabilitiesMember |
[1] | Represents the netting of derivative receivable and payable balance for the same counterparty under enforceable master netting arrangements if the Company has elected to net.
[2] | Represents $6.5 million and $3.5 million of cash collateral received against derivative assets with the same counterparty that are subject to enforceable master netting arrangements as of March 31, 2015 and December 31, 2014, respectively.
[3] | Represents cash and securities pledged against derivative liabilities with the same counterparty that are subject to enforceable master netting arrangements. Includes approximately $19.0 million and $12.8 million of cash collateral posted as of March 31, 2015 and December 31, 2014, respectively.

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