Electric utility segment - Schedule of Consolidating Statements of Changes in Common Stock Equity (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Increase (decrease) in stockholders' equity
Beginning balance	$ 1,479,089	$ 2,344,841	$ 2,202,499
Net income (loss) for common stock	123,120	(1,426,009)	199,238
Other comprehensive income (loss), net of taxes benefits	(123)	3,184	46,678
Issuance of common stock, net of expenses	250,000	575,000
Common stock dividends			(118,348)
Stock expense adjustment and other	(648)	(7,324)	1,791
Additional paid-in capital	287,790	270
Ending balance	1,605,919	1,479,089	2,344,841
Hawaiian Electric Company, Inc. and Subsidiaries
Increase (decrease) in stockholders' equity
Beginning balance	1,156,955	2,409,110	2,344,170
Net income (loss) for common stock	168,215	(1,226,362)	193,952
Other comprehensive income (loss), net of taxes benefits	(146)	(63)	(12)
Issuance of common stock, net of expenses		0
Common stock dividends	(30,000)	(26,000)	(129,000)
Stock expense adjustment and other	585
Additional paid-in capital	287,790	270
Ending balance	1,583,399	1,156,955	2,409,110
Consolidating adjustments | Hawaiian Electric Company, Inc. and Subsidiaries
Increase (decrease) in stockholders' equity
Beginning balance	(680,414)	(722,211)	(701,833)
Net income (loss) for common stock	(40,794)	248,004	(44,809)
Other comprehensive income (loss), net of taxes benefits	17	(77)	(19)
Issuance of common stock, net of expenses		(205,215)
Common stock dividends			24,450
Stock expense adjustment and other	(190)
Additional paid-in capital	(12,915)	(915)
Ending balance	(734,296)	(680,414)	(722,211)
Hawaiian Electric
Increase (decrease) in stockholders' equity
Beginning balance	1,479,089
Ending balance	1,605,919	1,479,089
Hawaiian Electric | Reportable Legal Entities | Hawaiian Electric Company, Inc. and Subsidiaries
Increase (decrease) in stockholders' equity
Beginning balance	1,156,955	2,409,110	2,344,170
Net income (loss) for common stock	168,215	(1,226,362)	193,952
Other comprehensive income (loss), net of taxes benefits	(146)	(63)	(12)
Common stock dividends	(30,000)	(26,000)	(129,000)
Stock expense adjustment and other	585
Additional paid-in capital	287,790	270
Ending balance	1,583,399	1,156,955	2,409,110
Hawaii Electric Light | Reportable Legal Entities | Hawaiian Electric Company, Inc. and Subsidiaries
Increase (decrease) in stockholders' equity
Beginning balance	243,964	359,790	344,720
Net income (loss) for common stock	24,741	(116,414)	28,507
Other comprehensive income (loss), net of taxes benefits	(7)	54	(12)
Common stock dividends			(13,425)
Stock expense adjustment and other	100
Additional paid-in capital	7,534	534
Ending balance	276,332	243,964	359,790
Maui Electric | Reportable Legal Entities | Hawaiian Electric Company, Inc. and Subsidiaries
Increase (decrease) in stockholders' equity
Beginning balance	282,876	362,344	357,036
Net income (loss) for common stock	10,122	(134,872)	16,302
Other comprehensive income (loss), net of taxes benefits	(10)	23	31
Issuance of common stock, net of expenses		55,000
Common stock dividends			(11,025)
Stock expense adjustment and other	90
Additional paid-in capital	5,381	381
Ending balance	298,459	282,876	362,344
Other subsidiaries | Reportable Legal Entities | Hawaiian Electric Company, Inc. and Subsidiaries
Increase (decrease) in stockholders' equity
Beginning balance	153,574	77	77
Net income (loss) for common stock	5,931	3,282
Other comprehensive income (loss), net of taxes benefits	0	0
Issuance of common stock, net of expenses		150,215
Ending balance	$ 159,505	$ 153,574	$ 77