Leases - Net Lease Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Net lease expense
Operating lease expense	$ 9,169	$ 9,158
Short-term lease expense	397	487
Variable lease expense	2,353	2,152
Finance lease expense:
Amortization of right-of-use assets	3	3
Interest on lease liabilities	1	2
Finance lease right-of use assets	$ 0	$ 0
Premises and equipment	fhb:PremisesAndEquipmentMember	fhb:PremisesAndEquipmentMember
Total finance lease expense	$ 4	$ 5
Less: Sublease income	(1,222)	(1,073)
Net lease expense	$ 10,701	$ 10,729