Bank of Hawaii Corporation Financial Statements - Schedule of Condensed Statements of Cash Flows (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Operating Activities
Net Income	$ 171,202	$ 225,804	$ 253,372
Adjustments to Reconcile Net Income to Net Cash Provided by Operating Activities:
Share-Based Compensation	15,656	16,066	13,267
Net Losses on Investment Securities	11,455	6,111	1,297
Net Change in Other Assets and Other Liabilities	(85,485)	13,608	27,989
Net Cash Provided by Operating Activities	150,221	332,960	377,151
Investing Activities
Purchases		(91,229)	(2,676,376)
Net Cash Provided by (Used in) Investing Activities	562,795	(1,253,418)	(2,423,334)
Financing Activities
Proceeds from Issuance of Common Stock	5,878	6,797	13,611
Proceeds from Issuance of Preferred Stock			175,487
Repurchase of Common Stock	(14,290)	(55,063)	(31,258)
Cash Dividends Paid on Common Stock	(111,795)	(112,557)	(110,633)
Cash Dividends Paid on Preferred Stock	(7,877)	(7,877)	(2,975)
Net Cash (Used in) Provided by Financing Activities	(113,839)	761,791	1,992,529
Net Change in Cash and Cash Equivalents	599,177	(158,667)	(53,654)
Cash and Cash Equivalents at Beginning of Period	401,767	560,434	614,088
Cash and Cash Equivalents at End of Period	1,000,944	401,767	560,434
Parent Company
Operating Activities
Net Income	171,202	225,804	253,372
Adjustments to Reconcile Net Income to Net Cash Provided by Operating Activities:
Share-Based Compensation	887	847	779
Net Losses on Investment Securities	1,394	1,195	948
Equity in Undistributed Income of Subsidiaries	(37,257)	(46,318)	(192,734)
Net Change in Other Assets and Other Liabilities	(585)	1,138	(977)
Net Cash Provided by Operating Activities	135,641	182,666	61,388
Investing Activities
Capital Contributions to the Bank of Hawai‘i			(165,000)
Expenses related to Sales of Investment Securities	(1,394)	(1,195)	(948)
Net Cash Provided by (Used in) Investing Activities	(1,394)	(1,195)	(165,948)
Financing Activities
Proceeds from Issuance of Common Stock	5,878	6,797	13,611
Proceeds from Issuance of Preferred Stock			175,487
Repurchase of Common Stock	(14,290)	(55,063)	(31,258)
Cash Dividends Paid on Common Stock	(111,795)	(112,557)	(110,633)
Cash Dividends Paid on Preferred Stock	(7,877)	(7,877)	(2,975)
Net Cash (Used in) Provided by Financing Activities	(128,084)	(168,700)	44,232
Net Change in Cash and Cash Equivalents	6,163	12,771	(60,328)
Cash and Cash Equivalents at Beginning of Period	19,147	6,376	66,704
Cash and Cash Equivalents at End of Period	$ 25,310	$ 19,147	$ 6,376