Basis of presentation (Details) $ in Thousands, shares in Millions	1 Months Ended	3 Months Ended						9 Months Ended
	Sep. 30, 2024 USD ($) shares	Sep. 30, 2024 USD ($)	Jun. 30, 2024 USD ($)	Mar. 31, 2024 USD ($)	Sep. 30, 2023 USD ($)	Jun. 30, 2023 USD ($)	Mar. 31, 2023 USD ($)	Sep. 30, 2024 USD ($)	Sep. 30, 2023 USD ($)	Nov. 01, 2024 USD ($) installment	Dec. 31, 2023 USD ($)
Loss Contingencies [Line Items]
Net losses incurred		$ 104,402	$ 1,295,484	$ (42,122)	$ (41,118)	$ (54,610)	$ (54,721)	$ 1,357,764	$ (150,449)
Wildfire tort-related claims	$ 1,915,000	1,915,000						1,915,000			$ 75,000
Cash and cash equivalents	1,159,635	1,159,635			667,129			1,159,635	667,129		679,546
Hawaiian Electric
Loss Contingencies [Line Items]
Cash and cash equivalents	677,700	677,700						677,700
Maui Windstorm and Wildfires | Natural Disasters and Other Casualty Events | Tort-Related Legal Claims | Subsequent Event
Loss Contingencies [Line Items]
Installment payments | installment										4
Hawaiian Electric Company, Inc. and Subsidiaries
Loss Contingencies [Line Items]
Net losses incurred		82,585	$ 1,229,394	$ (39,221)	(43,461)	$ (45,299)	$ (47,009)	1,272,758	(135,769)
Wildfire tort-related claims	1,920,000	1,920,000						1,920,000
Settlement accrual, current liability	478,750	478,750						478,750			75,000
Settlement accrual, non-current liabilities	$ 1,436,250	1,436,250						1,436,250			0
Sale of stock, number of shares issued (in shares) | shares	62.2
Sale of stock, received on transaction	$ 557,700
Cash and cash equivalents	147,624	$ 147,624			$ 274,854			$ 147,624	$ 274,854		$ 106,077
Hawaiian Electric Company, Inc. and Subsidiaries | Subsequent Event
Loss Contingencies [Line Items]
Settlement accrual, current liability										$ 479,000
Hawaiian Electric Company, Inc. and Subsidiaries | Over-Allotment Option
Loss Contingencies [Line Items]
Sale of stock, received on transaction	$ 250,000