Condensed Consolidated Statements of Changes in Common Stock Equity (unaudited) - HECO - USD ($) $ in Thousands	Total	Hawaiian Electric Company, Inc. and Subsidiaries	Common stock	Common stock Hawaiian Electric Company, Inc. and Subsidiaries	Premium on capital stock Hawaiian Electric Company, Inc. and Subsidiaries	Retained earnings	Retained earnings Hawaiian Electric Company, Inc. and Subsidiaries	Accumulated other comprehensive income (loss)	Accumulated other comprehensive income (loss) Hawaiian Electric Company, Inc. and Subsidiaries
Beginning balance (in shares) at Dec. 31, 2022			109,471,000	17,854,000
Beginning balance at Dec. 31, 2022	$ 2,202,499	$ 2,344,170	$ 1,692,697	$ 119,048	$ 810,955	$ 845,830	$ 1,411,306	$ (336,028)	$ 2,861
Increase (decrease) in stockholders' equity
Net income (loss) for common stock	54,721	47,009				54,721	47,009
Other comprehensive income (loss), net of tax benefits	20,488	(45)						20,488	(45)
Common stock dividends	(39,446)	(32,250)				(39,446)	(32,250)
Ending balance (in shares) at Mar. 31, 2023			109,572,000	17,854,000
Ending balance at Mar. 31, 2023	2,237,955	2,358,884	$ 1,692,390	$ 119,048	810,955	861,105	1,426,065	(315,540)	2,816
Beginning balance (in shares) at Dec. 31, 2022			109,471,000	17,854,000
Beginning balance at Dec. 31, 2022	2,202,499	2,344,170	$ 1,692,697	$ 119,048	810,955	845,830	1,411,306	(336,028)	2,861
Increase (decrease) in stockholders' equity
Net income (loss) for common stock	150,449	135,769
Other comprehensive income (loss), net of tax benefits	(21,996)	(166)
Common stock dividends		(96,750)
Ending balance (in shares) at Sep. 30, 2023			110,086,000	17,854,000
Ending balance at Sep. 30, 2023	2,224,354	2,383,023	$ 1,704,447	$ 119,048	810,955	877,931	1,450,325	(358,024)	2,695
Beginning balance (in shares) at Mar. 31, 2023			109,572,000	17,854,000
Beginning balance at Mar. 31, 2023	2,237,955	2,358,884	$ 1,692,390	$ 119,048	810,955	861,105	1,426,065	(315,540)	2,816
Increase (decrease) in stockholders' equity
Net income (loss) for common stock	54,610	45,299				54,610	45,299
Other comprehensive income (loss), net of tax benefits	(7,609)	(44)						(7,609)	(44)
Common stock dividends	(39,447)	(32,250)				(39,447)	(32,250)
Ending balance (in shares) at Jun. 30, 2023			109,612,000	17,854,000
Ending balance at Jun. 30, 2023	2,249,377	2,371,889	$ 1,696,258	$ 119,048	810,955	876,268	1,439,114	(323,149)	2,772
Increase (decrease) in stockholders' equity
Net income (loss) for common stock	41,118	43,461				41,118	43,461
Other comprehensive income (loss), net of tax benefits	(34,875)	(77)						(34,875)	(77)
Common stock dividends	(39,455)	(32,250)				(39,455)	(32,250)
Ending balance (in shares) at Sep. 30, 2023			110,086,000	17,854,000
Ending balance at Sep. 30, 2023	$ 2,224,354	2,383,023	$ 1,704,447	$ 119,048	810,955	877,931	1,450,325	(358,024)	2,695
Beginning balance (in shares) at Dec. 31, 2023	110,151,798		110,152,000	17,854,000
Beginning balance at Dec. 31, 2023	$ 2,344,841	2,409,110	$ 1,707,471	$ 119,048	810,955	926,720	1,476,258	(289,350)	2,849
Increase (decrease) in stockholders' equity
Net income (loss) for common stock	42,122	39,221				42,122	39,221
Other comprehensive income (loss), net of tax benefits	(9,801)	(49)						(9,801)	(49)
Common stock dividends		(13,000)					(13,000)
Ending balance (in shares) at Mar. 31, 2024			110,303,000	17,854,000
Ending balance at Mar. 31, 2024	$ 2,377,380	2,435,282	$ 1,707,689	$ 119,048	810,955	968,842	1,502,479	(299,151)	2,800
Beginning balance (in shares) at Dec. 31, 2023	110,151,798		110,152,000	17,854,000
Beginning balance at Dec. 31, 2023	$ 2,344,841	2,409,110	$ 1,707,471	$ 119,048	810,955	926,720	1,476,258	(289,350)	2,849
Increase (decrease) in stockholders' equity
Net income (loss) for common stock	(1,357,764)	(1,272,758)
Other comprehensive income (loss), net of tax benefits	$ 31,153	(93)
Common stock dividends		(26,000)
Ending balance (in shares) at Sep. 30, 2024	172,465,608		172,466,000	17,854,000
Ending balance at Sep. 30, 2024	$ 1,577,041	1,110,259	$ 2,266,282	$ 119,048	810,955	(431,044)	177,500	(258,197)	2,756
Beginning balance (in shares) at Mar. 31, 2024			110,303,000	17,854,000
Beginning balance at Mar. 31, 2024	2,377,380	2,435,282	$ 1,707,689	$ 119,048	810,955	968,842	1,502,479	(299,151)	2,800
Increase (decrease) in stockholders' equity
Net income (loss) for common stock	(1,295,484)	(1,229,394)				(1,295,484)	(1,229,394)
Other comprehensive income (loss), net of tax benefits	1,594	(46)						1,594	(46)
Common stock dividends		(13,000)					(13,000)
Ending balance (in shares) at Jun. 30, 2024			110,303,000	17,854,000
Ending balance at Jun. 30, 2024	1,085,273	1,192,842	$ 1,709,472	$ 119,048	810,955	(326,642)	260,085	(297,557)	2,754
Increase (decrease) in stockholders' equity
Net income (loss) for common stock	(104,402)	(82,585)				(104,402)	(82,585)
Other comprehensive income (loss), net of tax benefits	$ 39,360	2						39,360	2
Ending balance (in shares) at Sep. 30, 2024	172,465,608		172,466,000	17,854,000
Ending balance at Sep. 30, 2024	$ 1,577,041	$ 1,110,259	$ 2,266,282	$ 119,048	$ 810,955	$ (431,044)	$ 177,500	$ (258,197)	$ 2,756