Bank segment (HEI only) - Balance Sheets Data (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Assets
Cash and cash equivalents	$ 679,546	$ 199,877	$ 305,551
Investment securities
Available-for-sale investment securities	1,136,439	1,429,667
Held-to-maturity investment securities, at amortized cost	1,201,314	1,251,747
Held-to-maturity investment securities	1,103,668
Stock in Federal Home Loan Bank, at cost	14,728	26,560
Allowance for credit losses	(74,372)	(72,216)	(71,130)	$ (101,201)
Total loans, net	6,106,438	5,906,690
Loans held for sale, at lower of cost or fair value	15,168	824
Other	877,959	824,536
Goodwill	82,190	82,190
Total assets	17,243,821	16,284,244	15,822,637
LIABILITIES AND SHAREHOLDERS’ EQUITY
Other	853,349	787,057
Total liabilities	14,864,687	14,047,452
Commitments and contingencies
Retained earnings	926,720	845,830
Accumulated other comprehensive income (loss), net of taxes
Net unrealized losses on securities	(282,963)	(328,904)
Retirement benefit plans	(8,025)	(9,115)
Accumulated other comprehensive income (loss), net of taxes	(289,350)	(336,028)
Total shareholders’ equity	2,344,841	2,202,499	$ 2,390,884	$ 2,337,502
Total capitalization and liabilities	17,243,821	16,284,244
Other assets
Premises and equipment, net	6,150,126	5,687,003
Total other assets	877,959	824,536
Other liabilities
Total other liabilities	853,349	787,057
American Savings Bank (ASB)
Assets
Cash and due from banks	184,383	153,042
Interest-bearing deposits	251,072	3,107
Cash and cash equivalents	435,455	156,149
Investment securities
Available-for-sale investment securities	1,136,439	1,429,667
Held-to-maturity investment securities, at amortized cost	1,201,314	1,251,747
Held-to-maturity investment securities	1,103,668	1,150,971
Stock in Federal Home Loan Bank, at cost	14,728	26,560
Loans held for investment	6,180,810	5,978,906
Allowance for credit losses	(74,372)	(72,216)
Total loans, net	6,106,438	5,906,690
Loans held for sale, at lower of cost or fair value	15,168	824
Other	681,460	692,143
Goodwill	82,190	82,190
Total assets	9,673,192	9,545,970
LIABILITIES AND SHAREHOLDERS’ EQUITY
Deposit liabilities–noninterest-bearing	2,599,762	2,811,077
Deposit liabilities–interest-bearing	5,546,016	5,358,619
Other borrowings	750,000	695,120
Other	247,563	212,269
Total liabilities	9,143,341	9,077,085
Commitments and contingencies
Common stock	1	1
Premium on capital stock	358,067	355,806
Retained earnings	464,055	449,693
Accumulated other comprehensive income (loss), net of taxes
Net unrealized losses on securities	(282,963)	(328,904)
Retirement benefit plans	(9,309)	(7,711)
Accumulated other comprehensive income (loss), net of taxes	(292,272)	(336,615)
Total shareholders’ equity	529,851	468,885
Total capitalization and liabilities	9,673,192	9,545,970
Other assets
Bank-owned life insurance	187,857	182,986
Premises and equipment, net	187,042	195,324
Accrued interest receivable	28,472	25,077
Mortgage servicing rights	8,169	9,047
Low-income housing investments	112,234	106,978
Deferred income tax assets	104,292	116,441
Other	53,394	56,290
Total other assets	681,460	692,143
Other liabilities
Accrued expenses	115,231	97,295
Federal income taxes payable	0	863
Cashier’s checks	40,479	36,401
Advance payments by borrowers	10,107	9,637
Other	81,746	68,073
Total other liabilities	$ 247,563	$ 212,269