XML 84 R71.htm IDEA: XBRL DOCUMENT
v3.8.0.1

Loans Receivable and Allowance for Credit Losses (Loans Modified as TDRs that Subsequently Defaulted) (Details) $ in Thousands | 3 Months Ended |
--- | --- | ---
Mar. 31, 2018 USD ($) loan | Mar. 31, 2017 USD ($) loan | Dec. 31, 2017 USD ($)
Financing Receivable, Modifications [Line Items] |  |  |
Period beyond which a TDR generally becomes delinquent | 90 days |  |
Additional funds committed to lend to borrowers whose terms have been modified | $ 2,000 |  | $ 5,100
Non-PCI Loans | Commercial lending | Commercial and industrial (“C&I”) |  |  |
Financing Receivable, Modifications [Line Items] |  |  |
Number of Loans | loan | 0 | 1 |
Recorded Investment | $ 0 | $ 2,718 |
Non-PCI Loans | Consumer lending | Home equity lines of credit (“HELOCs”) |  |  |
Financing Receivable, Modifications [Line Items] |  |  |
Number of Loans | loan | 1 | 0 |
Recorded Investment | $ 155 | $ 0 |

X
- Definition Duration of delinquency related to troubled debt restructuring loans where it becomes a nonaccrual loan and is considered to have defaulted. + References No definition available. + Details
Name: | ewbc_NumberOfDaysTroubledDebtRestructuringsBecomeDelinquent
Namespace Prefix: | ewbc_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_FinancingReceivableModificationsLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of financing receivables that have been modified by troubled debt restructurings within the previous 12 months and for which there was a payment default. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 34 -URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953682-111524 + Details
Name: | us-gaap_FinancingReceivableModificationsSubsequentDefaultNumberOfContracts1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of investment related to financing receivables modified by troubled debt restructurings within the previous 12 months, for which there was a payment default. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 34 -URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953682-111524 + Details
Name: | us-gaap_FinancingReceivableModificationsSubsequentDefaultRecordedInvestment1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Reflects the unfunded portion of contractual agreements to lend funds to borrowers for loans whose terms have been modified by troubled debt restructuring. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 40 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=82895541&loc=d3e18794-111554 + Details
Name: | us-gaap_LoansAndLeasesReceivableImpairedCommitmentToLend
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Details
Name: | us-gaap_ReceivablesAcquiredWithDeterioratedCreditQualityAxis=ewbc_ReceivablesOriginatedOrAcquiredWithoutDeterioratedCreditQualityMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_CommercialPortfolioSegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=ewbc_CommercialAndIndustrialLoanMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_ConsumerPortfolioSegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_HomeEquityMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |