Condensed Consolidated Statements of Comprehensive Income (unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Statement of Comprehensive Income [Abstract]
Net income for common stock	$ 52,541	$ 63,872	$ 121,708	$ 128,230
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 $(32,529), $6,214, $(76,608) and $(10,402), respectively	(88,857)	16,976	(209,264)	(28,414)
Reclassification adjustment for net realized gains included in net income, net of taxes of nil, nil, nil and $(142), respectively	0	0	0	(387)
Derivatives qualifying as cash flow hedges:
Unrealized interest rate hedging gains (losses) arising during the period, net of taxes of $273, $(243), $1,319 and $299, respectively	786	(701)	3,803	861
Reclassification adjustment for net realized losses included in net income, net of taxes of $18, nil, $37 and nil, respectively	53	0	108	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 of $(2), $2,028, $1,516 and $4,055, respectively	122	6,008	4,623	12,018
Reclassification adjustment for impact of D&Os of the PUC included in regulatory assets, net of taxes of $19, $(2,016), $(1,481) and $(4,031), respectively	56	(5,811)	(4,269)	(11,622)
Other comprehensive income (loss), net of taxes	(87,840)	16,472	(204,999)	(27,544)
Comprehensive income (loss) attributable to Hawaiian Electric Industries, Inc.	$ (35,299)	$ 80,344	$ (83,291)	$ 100,686