Income taxes - Schedule of Components of Income Taxes Attributable to Net Income for Common Stock (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Federal
Current	$ 13,220	$ 22,206	$ 61,511
Deferred	(376,141)	1,951	(37,922)
Deferred tax credits, net	0	52	4,031
Federal taxes	(362,921)	24,209	27,620
State
Current	2,009	2,924	6,467
Deferred	(110,050)	7,401	4,772
Deferred tax credits, net	0	0	56
State taxes	(108,041)	10,325	11,295
Total	(470,962)	34,534	38,915
Hawaiian Electric Company, Inc. and Subsidiaries
Federal
Current	34,216	40,365	75,118
Deferred	(373,316)	(3,444)	(39,646)
Deferred tax credits, net	0	22	137
Federal taxes	(339,100)	36,943	35,609
State
Current	7,864	9,367	15,780
Deferred	(108,311)	4,883	(1,769)
Deferred tax credits, net	0	0	56
State taxes	(100,447)	14,250	14,067
Total	$ (439,547)	$ 51,193	$ 49,676