XML 94 R77.htm IDEA: XBRL DOCUMENT
v3.25.3

Affordable Housing Partnership, Tax Credit and Community Reinvestment Act Investments, Net - Narrative (Details) - USD ($) $ in Millions | 9 Months Ended |
--- | --- | ---
Sep. 30, 2025 | Dec. 31, 2024
Investments in Tax Credit and Other Investments, Net [Line Items] |  |
Minimum compliance period for qualified affordable housing partnerships to fully utilize the tax credits (in years) | 15 years |
Other Assets |  |
Investments in Tax Credit and Other Investments, Net [Line Items] |  |
Equity securities without readily determinable fair values | $ 117 | $ 118

X
- Definition Investments in Tax Credit and Other Investments, Net [Line Items] + References No definition available. + Details
Name: | ewbc_InvestmentsInTaxCreditAndOtherInvestmentsNetLineItems
Namespace Prefix: | ewbc_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Represents the minimum compliance period, to meet regulatory requirements for affordable housing, to fully utilize the tax credits. + References No definition available. + Details
Name: | ewbc_MinimumCompliancePeriodToFullyUtilizeTaxCredits
Namespace Prefix: | ewbc_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of investment in equity security without readily determinable fair value. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 321 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 3 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479536/321-10-50-3 + Details
Name: | us-gaap_EquitySecuritiesWithoutReadilyDeterminableFairValueAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Details
Name: | us-gaap_BalanceSheetLocationAxis=us-gaap_OtherAssetsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |