SCHEDULE I - CONDENSED FINANCIAL INFORMATION OF REGISTRANT - 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 cash provided by operating activities	$ 454,476	$ 375,673	$ 429,407
Cash flows from investing activities
Capital expenditures	(344,037)	(314,524)	(383,895)
Other, net	13,046	27	3,412
Net cash used in investing activities	(1,128,682)	(1,179,592)	(1,413,648)
Cash flows from financing activities
Net decrease in short-term borrowings with original maturities of three months or less	83,652	(10,493)	(71,219)
Proceeds from issuance of short-term debt	35,000	0	165,000
Repayment of short-term debt	0	(65,000)	(150,000)
Proceeds from issuance of long-term debt	227,312	285,886	415,997
Repayment of long-term debt	(221,910)	(82,262)	(178,969)
Withheld shares for employee taxes on vested share-based compensation	(3,165)	(2,006)	(5,700)
Common stock dividends	(153,229)	(148,643)	(144,096)
Other	(2,398)	(3,080)	(3,203)
Net cash used in financing activities	567,671	756,402	1,115,535
Net increase (decrease) in cash and equivalents	(106,535)	(47,517)	131,294
Cash, cash equivalents and restricted cash, January 1	311,462	358,979	227,685
Cash, cash equivalents and restricted cash, December 31	204,927	311,462	358,979
Hawaiian Electric (parent only)
Cash flows from operating activities
Net cash provided by operating activities	167,150	154,151	134,363
Cash flows from investing activities
Increase in note receivable from subsidiary	(1,140)	0	0
Decrease in note receivable from subsidiary	0	0	22,719
Capital expenditures	(224)	(10)	(20)
Investments in subsidiaries	(50,629)	(76,232)	(42,664)
Other, net	1,662	180	2,435
Net cash used in investing activities	(50,331)	(76,062)	(17,530)
Cash flows from financing activities
Net decrease in short-term borrowings with original maturities of three months or less	(4,315)	(10,493)	(32,232)
Proceeds from issuance of short-term debt	35,000	0	65,000
Repayment of short-term debt	0	(15,000)	(50,000)
Proceeds from issuance of long-term debt	160,000	150,000	50,000
Repayment of long-term debt	(150,000)	(50,000)	0
Proceeds from issuance of syndicated credit facility	0	0	66,300
Repayment of syndicated credit facility	0	0	(66,300)
Withheld shares for employee taxes on vested share-based compensation	(3,165)	(2,006)	(5,700)
Common stock dividends	(153,229)	(148,643)	(144,096)
Other	(978)	(1,767)	(459)
Net cash used in financing activities	(116,687)	(77,909)	(117,487)
Net increase (decrease) in cash and equivalents	132	180	(654)
Cash, cash equivalents and restricted cash, January 1	479	299	953
Cash, cash equivalents and restricted cash, December 31	$ 611	$ 479	$ 299