Parent Company - Condensed Statements of Cash Flows (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Cash flows from operating activities
Net income	$ 185,754	$ 284,392	$ 264,394
Adjustments to reconcile net income to net cash provided by operating activities:
Deferred income taxes	(19,396)	17,060	(3,602)
Stock-based compensation	10,028	7,826	6,185
Change in assets and liabilities:
Net (increase) decrease in other assets	(17,880)	(20,923)	11,859
Net increase (decrease) in other liabilities	(114,613)	(76,303)	(27,090)
Net cash provided by operating activities	209,506	296,504	351,413
Cash flows from investing activities
Other, net	186	2	(2,767)
Net cash provided by investing activities	(2,103,763)	375,212	(257,809)
Cash flows from financing activities
Dividends paid	(135,099)	(138,246)	(131,036)
Stock tendered for payment of withholding taxes	(1,749)	(1,764)	(53)
Proceeds from employee stock purchase plan	312		342
Common stock repurchased	(5,000)	(136,242)	(131,800)
Net cash provided by (used in) financing activities	2,241,184	(981,336)	(124,611)
Net increase (decrease) in cash and cash equivalents	346,927	(309,620)	(31,007)
Cash and cash equivalents at beginning of year	694,017	1,003,637	1,034,644
Cash and cash equivalents at end of year	1,040,944	694,017	1,003,637
Parent Company.
Adjustments to reconcile net income to net cash provided by operating activities:
(Equity in undistributed income) excess distributions of FHB	(49,580)	10,620	(8,752)
Deferred income taxes	5	85	(48)
Stock-based compensation	713	84	281
Change in assets and liabilities:
Net (increase) decrease in other assets	(1,451)	5,318	(9,635)
Net increase (decrease) in other liabilities	(294)	(5,439)	7,633
Net cash provided by operating activities	135,147	295,060	253,873
Cash flows from financing activities
Dividends paid	(135,099)	(138,246)	(131,036)
Stock tendered for payment of withholding taxes	(1,749)	(1,764)	(69)
Proceeds from employee stock purchase plan	312		342
Common stock repurchased	(5,000)	(136,242)	(131,800)
Net cash provided by (used in) financing activities	(141,536)	(276,252)	(262,563)
Net increase (decrease) in cash and cash equivalents	(6,389)	18,808	(8,690)
Cash and cash equivalents at beginning of year	24,455	5,647	14,337
Cash and cash equivalents at end of year	$ 18,066	$ 24,455	$ 5,647