Electric utility segment - Regulatory Assets and Liabilities (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Regulatory assets
Regulatory assets	$ 242,513	$ 565,543
Regulatory liabilities
Regulatory liabilities	1,055,650	996,768
Hawaiian Electric Company, Inc. and Subsidiaries
Regulatory assets
Regulatory assets	242,513	565,543
Regulatory liabilities
Regulatory liabilities	1,055,650	996,768
Cost of removal in excess of salvage value | Hawaiian Electric Company, Inc. and Subsidiaries
Regulatory liabilities
Regulatory liabilities	577,985	562,514
Income taxes | Hawaiian Electric Company, Inc. and Subsidiaries
Regulatory liabilities
Regulatory liabilities	316,947	337,304
Decoupling revenue balancing account and RAM | Hawaiian Electric Company, Inc. and Subsidiaries
Regulatory liabilities
Regulatory liabilities	10,426	251
Retirement benefit plans | Hawaiian Electric Company, Inc. and Subsidiaries
Regulatory liabilities
Regulatory liabilities	81,950	51,734
Solar tax credits | Hawaiian Electric Company, Inc. and Subsidiaries
Regulatory liabilities
Regulatory liabilities	50,240	27,123
Other | Hawaiian Electric Company, Inc. and Subsidiaries
Regulatory liabilities
Regulatory liabilities	$ 18,102	17,842
Minimum | Cost of removal in excess of salvage value | Hawaiian Electric Company, Inc. and Subsidiaries
Regulatory liabilities
Authorized amortization or recovery periods	1 year
Minimum | Income taxes | Hawaiian Electric Company, Inc. and Subsidiaries
Regulatory liabilities
Authorized amortization or recovery periods	3 years
Minimum | Decoupling revenue balancing account and RAM | Hawaiian Electric Company, Inc. and Subsidiaries
Regulatory liabilities
Authorized amortization or recovery periods	1 year
Minimum | Solar tax credits | Hawaiian Electric Company, Inc. and Subsidiaries
Regulatory liabilities
Authorized amortization or recovery periods	1 year
Minimum | Other | Hawaiian Electric Company, Inc. and Subsidiaries
Regulatory liabilities
Remaining amortization or recovery periods	1 year
Maximum | Cost of removal in excess of salvage value | Hawaiian Electric Company, Inc. and Subsidiaries
Regulatory liabilities
Authorized amortization or recovery periods	79 years
Maximum | Income taxes | Hawaiian Electric Company, Inc. and Subsidiaries
Regulatory liabilities
Authorized amortization or recovery periods	37 years
Maximum | Decoupling revenue balancing account and RAM | Hawaiian Electric Company, Inc. and Subsidiaries
Regulatory liabilities
Authorized amortization or recovery periods	2 years
Maximum | Solar tax credits | Hawaiian Electric Company, Inc. and Subsidiaries
Regulatory liabilities
Authorized amortization or recovery periods	19 years
Maximum | Other | Hawaiian Electric Company, Inc. and Subsidiaries
Regulatory liabilities
Remaining amortization or recovery periods	3 years
Current assets | Hawaiian Electric Company, Inc. and Subsidiaries
Regulatory assets
Regulatory assets	$ 52,273	66,664
Long-term assets | Hawaiian Electric Company, Inc. and Subsidiaries
Regulatory assets
Regulatory assets	190,240	498,879
Current liabilities | Hawaiian Electric Company, Inc. and Subsidiaries
Regulatory liabilities
Regulatory liabilities	31,475	29,760
Long-term liabilities | Hawaiian Electric Company, Inc. and Subsidiaries
Regulatory liabilities
Regulatory liabilities	1,024,175	967,008
Retirement benefit plans (balance primarily varies with plans’ funded statuses) | Hawaiian Electric Company, Inc. and Subsidiaries
Regulatory assets
Regulatory assets	69,919	351,070
Income taxes | Hawaiian Electric Company, Inc. and Subsidiaries
Regulatory assets
Regulatory assets	$ 82,583	88,087
Income taxes | Minimum | Hawaiian Electric Company, Inc. and Subsidiaries
Regulatory assets
Authorized amortization or recovery periods	3 years
Income taxes | Maximum | Hawaiian Electric Company, Inc. and Subsidiaries
Regulatory assets
Authorized amortization or recovery periods	37 years
Decoupling revenue balancing account and RAM | Hawaiian Electric Company, Inc. and Subsidiaries
Regulatory assets
Regulatory assets	$ 14,290	31,607
Decoupling revenue balancing account and RAM | Minimum | Hawaiian Electric Company, Inc. and Subsidiaries
Regulatory assets
Authorized amortization or recovery periods	1 year
Decoupling revenue balancing account and RAM | Maximum | Hawaiian Electric Company, Inc. and Subsidiaries
Regulatory assets
Authorized amortization or recovery periods	2 years
Unamortized expense and premiums on retired debt and equity issuances | Hawaiian Electric Company, Inc. and Subsidiaries
Regulatory assets
Regulatory assets	$ 5,967	7,300
Unamortized expense and premiums on retired debt and equity issuances | Minimum | Hawaiian Electric Company, Inc. and Subsidiaries
Regulatory assets
Authorized amortization or recovery periods	1 year
Remaining amortization or recovery periods	1 year
Unamortized expense and premiums on retired debt and equity issuances | Maximum | Hawaiian Electric Company, Inc. and Subsidiaries
Regulatory assets
Authorized amortization or recovery periods	28 years
Remaining amortization or recovery periods	28 years
Vacation earned, but not yet taken | Hawaiian Electric Company, Inc. and Subsidiaries
Regulatory assets
Regulatory assets	$ 14,109	14,255
Authorized amortization or recovery periods	1 year
COVID-19 related costs (to be determined by PUC) | Hawaiian Electric Company, Inc. and Subsidiaries
Regulatory assets
Regulatory assets	$ 11,403	27,839
ECRC and PPAC | Hawaiian Electric Company, Inc. and Subsidiaries
Regulatory assets
Regulatory assets	$ 20,369	21,386
Authorized amortization or recovery periods	1 year
Other | Hawaiian Electric Company, Inc. and Subsidiaries
Regulatory assets
Regulatory assets	$ 23,873	$ 23,999
Other | Minimum | Hawaiian Electric Company, Inc. and Subsidiaries
Regulatory assets
Remaining amortization or recovery periods	1 year
Other | Maximum | Hawaiian Electric Company, Inc. and Subsidiaries
Regulatory assets
Remaining amortization or recovery periods	37 years