XML 97 R86.htm IDEA: XBRL DOCUMENT
v3.19.2

Commitments and Contingent Liabilities - Contingencies (Details) - USD ($) $ in Millions | 3 Months Ended | 6 Months Ended
--- | --- | ---
Sep. 30, 2018 | Jun. 30, 2019
Contingencies |  |
Settlement agreement |  | $ 4.1
Overdraft fee litigation |  |
Contingencies |  |
Settlement agreement | $ 4.1 |
First Hawaiian Bank (FHB) |  |
Contingencies |  |
Period for one-time continuous negative balance overdraft fee |  | 7 days

X
- Definition Represents, for an overdrawn demand deposit account, the period the account remains in a negative balance after which a one-time continuous negative balance overdraft fee to be assessed. + References No definition available. + Details
Name: | fhb_OverdrawnDemandDepositAccountPeriodForOneTimeContinuousNegativeBalanceOverdraftFee
Namespace Prefix: | fhb_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount awarded to other party in judgment or settlement of litigation. + References No definition available. + Details
Name: | us-gaap_LitigationSettlementAmountAwardedToOtherParty
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
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_LossContingenciesLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | srt_LitigationCaseAxis=fhb_OverdraftFeeLitigationMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | dei_LegalEntityAxis=fhb_FirstHawaiianBankMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |