XML 51 R41.htm IDEA: XBRL DOCUMENT
v3.22.2

Organization and Basis of Presentation - Basis of Presentation (Details) - USD ($) | 3 Months Ended | 6 Months Ended | 12 Months Ended
--- | --- | --- | ---
Jun. 30, 2022 | Jun. 30, 2022 | Dec. 31, 2021
Capitalization |  |  |
Investment securities comprised of collateralized loan obligations rated AA or better and obligations issued by local state and political subdivisions rated AA or better |  | 4.00% | 4.00%
Credit losses recognized on securities | $ 0 | $ 0 | $ 0
First Hawaiian, Inc. (FHI) |  |  |
Capitalization |  |  |
Outstanding common stock owned (as a percent) | 100.00% | 100.00% |

X
- Definition Percentage of securities comprised of collateralized loan obligations rated AA or better and obligations issued by local state and political subdivisions rated AA or better. + References No definition available. + Details
Name: | fhb_PercentageOfSecuritiesComprisedOfCollateralizedLoanObligationsRatedAaOrBetterAndObligationsIssuedByLocalStateAndPoliticalSubdivisionsRatedAaOrBetter
Namespace Prefix: | fhb_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of increase (decrease) in allowance for credit loss of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale). + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 30 -Section 50 -Paragraph 9 -URI http://asc.fasb.org/extlink&oid=124269663&loc=SL82922900-210455 + Details
Name: | us-gaap_DebtSecuritiesAvailableForSaleAllowanceForCreditLossPeriodIncreaseDecrease
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | na
Period Type: | duration

X
- Definition The parent entity's interest in net assets of the subsidiary, expressed as a percentage. + References No definition available. + Details
Name: | us-gaap_MinorityInterestOwnershipPercentageByParent
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | instant

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_ScheduleOfCapitalizationEquityLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | srt_OwnershipAxis=fhb_FirstHawaiianIncorporatedMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |