SCHEDULE I - CONDENSED FINANCIAL INFORMATION OF REGISTRANT - STATEMENTS OF CASH FLOWS (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Cash flows from operating activities
Net cash provided by (used in) operating activities	$ 487,481	$ 551,471	$ 454,476
Cash flows from investing activities
Capital expenditures	(344,251)	(442,727)	(339,333)
Other, net	10,330	6,558	14,184
Net cash used in investing activities	258,318	(257,399)	(1,128,682)
Cash flows from financing activities
Net decrease in short-term borrowings with original maturities of three months or less	0	(137,650)	83,652
Proceeds from issuance of short-term debt	50,000	65,000	35,000
Repayment of short-term debt	0	(100,000)	0
Proceeds from issuance of long-term debt	5,475	625,000	227,312
Repayment of long-term debt and funds transferred for repayment of long-term debt	(97,698)	(167,080)	(221,910)
Withheld shares for employee taxes on vested share-based compensation	(1,074)	(2,371)	(3,165)
Net proceeds from issuance of common stock	556,612	1,223	0
Common stock dividends	0	(73,957)	(111,229)
Other	(13,867)	(5,133)	(2,041)
Net cash provided by (used in) financing activities	154,705	195,575	567,671
Net increase (decrease) in cash, cash equivalents and restricted cash, including cash from discontinued operations	900,504	489,647	(106,535)
Cash, cash equivalents and restricted cash, including cash from discontinued operations, January 1	694,574	204,927	311,462
Cash, cash equivalents and restricted cash, including cash from discontinued operations, December 31	1,595,078	694,574	204,927
Less: Restricted cash	(492,317)	(15,028)	(5,050)
Cash and cash equivalents from continuing operations, December 31	750,535	244,091	43,728
Hawaiian Electric
Cash flows from operating activities
Net cash provided by (used in) operating activities	(9,324)	131,873	167,150
Cash flows from investing activities
Increase in note receivable from subsidiary	(5,004)	(3,542)	(1,140)
Decrease in note receivable from subsidiary	0	0	0
Capital expenditures	(214)	(21)	(224)
Dividend from subsidiary	400,950	0	0
Investments in subsidiaries	(510,650)	(12,246)	(50,629)
Other, net	(1,518)	610	1,662
Net cash used in investing activities	(116,436)	(15,199)	(50,331)
Cash flows from financing activities
Net decrease in short-term borrowings with original maturities of three months or less	0	(49,683)	(4,315)
Proceeds from issuance of short-term debt	0	65,000	35,000
Repayment of short-term debt	0	(100,000)	0
Proceeds from issuance of long-term debt	0	100,000	160,000
Repayment of long-term debt and funds transferred for repayment of long-term debt	0	(50,000)	(150,000)
Proceeds from issuance of revolving credit facility	0	175,000	0
Repayment of syndicated credit facility	(2,000)	0	0
Withheld shares for employee taxes on vested share-based compensation	(1,074)	(2,371)	(3,165)
Net proceeds from issuance of common stock	556,612	1,223	0
Common stock dividends	0	(112,957)	(153,229)
Other	0	(771)	(978)
Net cash provided by (used in) financing activities	553,538	25,441	(116,687)
Net increase (decrease) in cash, cash equivalents and restricted cash, including cash from discontinued operations	427,778	142,115	132
Cash, cash equivalents and restricted cash, including cash from discontinued operations, January 1	142,726	611	479
Cash, cash equivalents and restricted cash, including cash from discontinued operations, December 31	570,504	142,726	611
Less: Restricted cash	(6,320)	(6,216)	0
Cash and cash equivalents from continuing operations, December 31	$ 564,184	$ 136,510	$ 611