Condensed Consolidated Statements of Comprehensive Income (unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Statement of Comprehensive Income [Abstract]
Net income for common stock	$ 42,122	$ 54,721
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 $(4,975) and $6,079, respectively	(13,589)	16,605
Amortization of unrealized holding losses on held-to-maturity securities, net of taxes of $1,129 and $1,346, respectively	3,086	3,677
Derivatives qualifying as cash flow hedges:
Unrealized interest rate hedging gains (losses) arising during the period, net of taxes of $256 and $65, respectively	740	186
Reclassification adjustment to net income, net of taxes of $(16) and $(17), respectively	(48)	(48)
Retirement benefit plans:
Adjustment for amortization of prior service credit and net gains recognized during the period in net periodic benefit cost, net of taxes of $(154) and $(122), respectively	(449)	(357)
Reclassification adjustment for impact of D&Os of the PUC included in regulatory assets, net of taxes of $159 and $147, respectively	459	425
Other comprehensive loss, net of taxes	(9,801)	20,488
Comprehensive income attributable to Hawaiian Electric Industries, Inc.	$ 32,321	$ 75,209