Parent Company - Condensed Statements of Comprehensive Income (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Income
Total revenue	$ 715,475	$ 733,114	$ 765,935
Noninterest expense
Salaries and employee benefits	182,384	174,221	173,098
Contracted services and professional fees	63,349	60,546	56,321
Equipment	24,719	20,277	17,343
Other	66,082	47,339	50,661
Total noninterest expense	405,479	367,672	370,437
Benefit for income taxes	(83,261)	(57,970)	(97,306)
Net income	265,735	185,754	284,392
Comprehensive income	112,438	249,107	384,838
First Hawaiian, Inc.
Income
Dividends from FHB	213,500	142,000	300,300
Other income		1,169	1,691
Total revenue	213,500	143,169	301,991
Noninterest expense
Salaries and employee benefits	3,732	3,660	5,241
Contracted services and professional fees	2,731	2,544	2,689
Equipment		31
Other	1,314	1,439	721
Total noninterest expense	7,777	7,674	8,651
Income before benefit for income taxes and equity in undistributed income (excess distributions) of FHB	205,723	135,495	293,340
Benefit for income taxes	1,877	679	1,672
Equity in undistributed income (excess distributions) of FHB	$ 58,135	$ 49,580	$ (10,620)