Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Statement of Comprehensive Income [Abstract]
Net income for common stock	$ 199,238	$ 241,138	$ 246,166
Net unrealized gains (losses) on available-for sale investment securities:
Net unrealized gains (losses) on available-for sale investment securities arising during the period, net of taxes of $7,536, $(110,140) and $(18,903) for 2023, 2022 and 2021, respectively	20,589	(300,860)	(51,636)
Reclassification adjustment for net realized losses (gains) included in net income, net of taxes of $4,011, nil and $(142) for 2023, 2022 and 2021, respectively	10,954	0	(387)
Amortization of unrealized holding losses on held-to-maturity securities, net of taxes of $5,271, $1,462 and nil for 2023, 2022 and 2021, respectively	14,398	3,993	0
Derivatives qualified as cash flow hedges:
Unrealized interest rate hedging gains (losses), net of taxes of $(58), $1,892 and $(108) for 2023, 2022 and 2021, respectively	(167)	5,457	(312)
Reclassification adjustment to net income, net of taxes of $(65), $60 and $13 for 2023, 2022 and 2021, respectively	(186)	172	37
Retirement benefit plans:
Net gains arising during the period, net of taxes of $3,778, $65,174 and $53,068 for 2023, 2022 and 2021, respectively	10,854	188,020	153,121
Adjustment for amortization of prior service credit and net losses (gains) recognized during the period in net periodic benefit cost, net of taxes of $(535), $6,820 and $6,665 for 2023, 2022 and 2021, respectively	(1,560)	19,659	19,253
Reclassification adjustment for impact of D&Os of the PUC included in regulatory assets, net of taxes of $(2,846), $(69,345) and $(59,429) for 2023, 2022 and 2021, respectively	(8,204)	(199,936)	(171,345)
Other comprehensive income (loss), net of taxes	46,678	(283,495)	(51,269)
Comprehensive income attributable to Hawaiian Electric Industries, Inc.	$ 245,916	$ (42,357)	$ 194,897