Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Net Investment	Common Stock	Additional Paid-In Capital	Retained Earnings	Accumulated Other Comprehensive Loss	Total
Balance at Dec. 31, 2015	$ 2,788,200				$ (51,259)	$ 2,736,941
Balance (in shares) at Dec. 31, 2015		139,459,620
Increase (Decrease) in Stockholders' Equity
Net income | Subsequent to reorganization on April 1, 2016				$ 54,860		54,860
Net income | Prior to reorganization on April 1, 2016	65,531					65,531
Net income						120,391
Distributions | Subsequent to reorganization on April 1, 2016			$ (70,724)			(70,724)
Distributions | Prior to reorganization on April 1, 2016	(363,624)					(363,624)
Contributions			61,992			61,992
Recapitalization of First Hawaiian, Inc.	$ (2,490,107)	$ 1,395	2,488,712
Cash dividends declared ($0.44 and $0.22 per share for six months ended June 30, 2017 and 2016, respectively)				(30,000)		(30,000)
Other comprehensive income, net of tax					46,032	46,032
Balance at Jun. 30, 2016		$ 1,395	2,479,980	24,860	(5,227)	2,501,008
Balance (in shares) at Jun. 30, 2016		139,459,620
Balance at Mar. 31, 2016					(18,373)
Increase (Decrease) in Stockholders' Equity
Net income						54,860
Other comprehensive income, net of tax					13,146	13,146
Balance at Jun. 30, 2016		$ 1,395	2,479,980	24,860	(5,227)	2,501,008
Balance (in shares) at Jun. 30, 2016		139,459,620
Balance at Dec. 31, 2016		$ 1,395	2,484,251	78,850	(88,011)	$ 2,476,485
Balance (in shares) at Dec. 31, 2016		139,530,654				139,530,654
Increase (Decrease) in Stockholders' Equity
Net income				113,635		$ 113,635
Cash dividends declared ($0.44 and $0.22 per share for six months ended June 30, 2017 and 2016, respectively)				(61,400)		(61,400)
Common stock issued under Employee Stock Purchase Plan			528			528
Common stock issued under Employee Stock Purchase Plan (in shares)		15,961
Equity-based awards			3,312	(318)		2,994
Other comprehensive income, net of tax					20,360	20,360
Balance at Jun. 30, 2017		$ 1,395	2,488,091	130,767	(67,651)	$ 2,552,602
Balance (in shares) at Jun. 30, 2017		139,546,615				139,546,615
Balance at Mar. 31, 2017					(86,692)
Increase (Decrease) in Stockholders' Equity
Net income						$ 56,895
Other comprehensive income, net of tax					19,041	19,041
Balance at Jun. 30, 2017		$ 1,395	$ 2,488,091	$ 130,767	$ (67,651)	$ 2,552,602
Balance (in shares) at Jun. 30, 2017		139,546,615				139,546,615