SCHEDULE I - CONDENSED FINANCIAL INFORMATION OF REGISTRANT - STATEMENTS OF INCOME (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2024	Sep. 30, 2024	Jun. 30, 2024	Mar. 31, 2024	Dec. 31, 2023	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Condensed Income Statements, Captions [Line Items]
Revenues	$ 799,180	$ 833,239	$ 795,417	$ 792,014	$ 853,424	$ 800,899	$ 798,800	$ 834,380	$ 3,219,850	$ 3,287,503	$ 3,420,917
Expenses
Depreciation of property, plant and equipment									261,701	254,990	244,477
Total expenses									4,926,610	3,012,511	3,141,362
Operating income (loss)	53,662	(149,720)	(1,661,589)	50,887	74,331	62,552	68,111	69,998	(1,706,760)	274,992	279,555
Less: Retirement defined benefits expense (credit)—other than service costs									(3,754)	(4,014)	(3,688)
Interest expense									127,207	125,532	103,402
Interest income									(19,362)	(9,105)	0
Income (loss) from continuing operations before income taxes									(1,791,595)	182,300	201,954
Income tax benefits									470,962	(34,534)	(38,915)
Income (loss) from continuing operations									(1,320,633)	147,766	163,039
Income (loss) from discontinued operations	(97,411)	18,778	(45,787)	20,934	3,231	11,365	20,204	18,562	(103,486)	53,362	79,989
Net income (loss) for common stock	$ (68,245)	$ (104,402)	$ (1,295,484)	$ 42,122	$ 48,789	$ 41,118	$ 54,610	$ 54,721	(1,426,009)	199,238	241,138
Hawaiian Electric
Condensed Income Statements, Captions [Line Items]
Revenues									492	268	320
Equity in net income (loss) of subsidiaries - continuing operations									(1,271,182)	186,170	193,087
Expenses
Operating, administrative and general									38,853	22,962	20,850
Depreciation of property, plant and equipment									409	402	399
Taxes, other than income taxes									1,120	864	732
Total expenses									40,382	24,228	21,981
Operating income (loss)									(1,311,072)	162,210	171,426
Less: Retirement defined benefits expense (credit)—other than service costs									383	289	147
Interest expense									39,406	32,630	21,997
Interest income									(12,729)	(2,651)	0
Income (loss) from continuing operations before income taxes									(1,338,132)	131,942	149,282
Income tax benefits									15,609	13,934	11,867
Income (loss) from continuing operations									(1,322,523)	145,876	161,149
Income (loss) from discontinued operations									(103,486)	53,362	79,989
Net income (loss) for common stock									$ (1,426,009)	$ 199,238	$ 241,138