Parent Company - Condensed Statements of Cash Flows (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Cash flows from operating activities
Net income	$ 265,685	$ 265,735	$ 185,754
Adjustments to reconcile net income to net cash provided by operating activities:
Deferred income taxes	22,138	14,120	(19,396)
Stock-based compensation	10,298	13,106	10,028
Change in assets and liabilities:
Net (increase) decrease in other assets	18,469	(8,211)	(17,880)
Net increase (decrease) in other liabilities	53,523	110,613	(114,613)
Net cash provided by operating activities	430,614	417,125	209,506
Cash flows from financing activities
Dividends paid	(132,588)	(134,133)	(135,099)
Stock tendered for payment of withholding taxes	(3,555)	(3,108)	(1,749)
Proceeds from employee stock purchase plan	379	547	312
Common stock repurchased	(9,478)	(75,000)	(5,000)
Net cash provided by (used in) financing activities	(197,359)	2,176,719	2,241,184
Net (decrease) increase in cash and cash equivalents	(731,845)	217,525	346,927
Cash and cash equivalents at beginning of year	1,258,469	1,040,944	694,017
Cash and cash equivalents at end of year	526,624	1,258,469	1,040,944
First Hawaiian, Inc.
Adjustments to reconcile net income to net cash provided by operating activities:
Equity in undistributed income of FHB	(117,801)	(58,135)	(49,580)
Deferred income taxes	22	36	5
Stock-based compensation	554	492	713
Change in assets and liabilities:
Net (increase) decrease in other assets	(4)	242	(1,451)
Net increase (decrease) in other liabilities	18	50	(294)
Net cash provided by operating activities	148,474	208,420	135,147
Cash flows from financing activities
Dividends paid	(132,588)	(134,133)	(135,099)
Stock tendered for payment of withholding taxes	(3,555)	(3,108)	(1,749)
Proceeds from employee stock purchase plan	379	547	312
Common stock repurchased	(9,478)	(75,000)	(5,000)
Net cash provided by (used in) financing activities	(145,242)	(211,694)	(141,536)
Net (decrease) increase in cash and cash equivalents	3,232	(3,274)	(6,389)
Cash and cash equivalents at beginning of year	14,792	18,066	24,455
Cash and cash equivalents at end of year	$ 18,024	$ 14,792	$ 18,066