Organization and Summary of Significant Accounting Policies - Cash and Due from Banks (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2015	Dec. 31, 2014
Organization and Summary of Significant Accounting Policies
Average cash reserves required with Federal Reserve Bank	$ 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