Condensed Consolidated Statements of Comprehensive Income (unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Statement of Comprehensive Income [Abstract]
Net income for common stock	$ 69,167	$ 64,358
Net unrealized gains (losses) on available-for-sale investment securities:
Net unrealized losses on available-for-sale investment securities arising during the period, net of taxes of $(44,079) and $(16,616), respectively	(120,407)	(45,390)
Reclassification adjustment for net realized gains included in net income, net of taxes of $— and $(142), respectively	0	(387)
Derivatives qualifying as cash flow hedges:
Unrealized interest rate hedging gains arising during the period, net of taxes of $1,046 and $542, respectively	3,017	1,562
Reclassification adjustment for net realized losses included in net income, net of taxes of $19 and nil, respectively	55	0
Retirement benefit plans:
Adjustment for amortization of prior service credit and net losses recognized during the period in net periodic benefit cost, net of taxes	4,501	6,010
Reclassification adjustment for impact of D&Os of the PUC included in regulatory assets, net of taxes	(4,325)	(5,811)
Other comprehensive loss, net of tax benefits	(117,159)	(44,016)
Comprehensive income (loss) attributable to Hawaiian Electric Industries, Inc.	$ (47,992)	$ 20,342