Organization and Summary of Significant Accounting Policies - VIEs and Cash and Due from Banks (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Organization and Summary of Significant Accounting Policies
Period over which affordable housing tax credits are recognized	10 years
Average cash reserves required with Federal Reserve Bank	$ 48.9	$ 38.0	$ 36.6

Represents the average cash reserves required to be maintained with the Federal Reserve Bank (FRB) during the period, determined based on the amount of deposits held.

No definition available.

Name:	fhb_AverageCashReservesRequiredFederalReserveBank
Namespace Prefix:	fhb_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration