Electric utility segment - Asset Retirement Obligations (Details) - Hawaiian Electric Company, Inc. and Subsidiaries - USD ($)	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Regulatory Projects and Legal Obligations [Line Items]
ARO, recognition impact on earnings	$ 0
Changes in the asset retirement obligation liability
Balance at the beginning of the period	11,110,000	$ 10,692,000
Accretion expense	442,000	423,000
Liabilities incurred	0	0
Liabilities settled	(4,000)	(5,000)
Balance at the end of the period	$ 11,548,000	$ 11,110,000