XML 95 R77.htm IDEA: XBRL DOCUMENT
v3.22.2.2

Investments in Qualified Affordable Housing Partnerships, Tax Credit and Other Investments, Net and Variable Interest Entities -Narrative (Details) - USD ($) | 3 Months Ended | 9 Months Ended |
--- | --- | --- | ---
Sep. 30, 2022 | Sep. 30, 2021 | Sep. 30, 2022 | Sep. 30, 2021 | Dec. 31, 2021
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 |  |
Adjustments to equity securities without readily determinable fair values | $ 0 | $ 0 | $ 0 | $ 0 |
Tax credit investments |  |  |  |  |
Investments in Tax Credit and Other Investments, Net [Line Items] |  |  |  |  |
Equity securities | 23,800,000 |  | 23,800,000 |  | $ 26,600,000
Investments in Tax Credit and Other Investments and Other Assets |  |  |  |  |
Investments in Tax Credit and Other Investments, Net [Line Items] |  |  |  |  |
Equity securities without readily determinable fair values | $ 34,600,000 |  | $ 34,600,000 |  | $ 33,100,000

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 measured at fair value with change in fair value recognized in net income (FV-NI), classified as current. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(2)) -URI https://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 Reference 2: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section 45 -Paragraph 1 -Subparagraph (f) -URI https://asc.fasb.org/extlink&oid=124098289&loc=d3e6676-107765 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 45 -Paragraph 1A -URI https://asc.fasb.org/extlink&oid=123594786&loc=SL75136599-209740 + Details
Name: | us-gaap_EquitySecuritiesFvNi
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of investment in equity security without readily determinable fair value. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 321 -SubTopic 10 -Section 50 -Paragraph 3 -Subparagraph (a) -URI https://asc.fasb.org/extlink&oid=126980263&loc=SL75117539-209714 + Details
Name: | us-gaap_EquitySecuritiesWithoutReadilyDeterminableFairValueAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of loss from downward price adjustment on investment in equity security without readily determinable fair value. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 321 -SubTopic 10 -Section 50 -Paragraph 3 -Subparagraph (b) -URI https://asc.fasb.org/extlink&oid=126980263&loc=SL75117539-209714 + Details
Name: | us-gaap_EquitySecuritiesWithoutReadilyDeterminableFairValueDownwardPriceAdjustmentAnnualAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

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

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