Segment financial information (Details) - USD ($) $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Sep. 30, 2022	Sep. 30, 2021	Dec. 31, 2021
Segment financial information
Revenues	$ 1,042,197			$ 756,904			$ 2,722,872	$ 2,080,107
Income (loss) before income taxes	79,905			78,151			233,602	241,291
Income taxes (benefit)	17,352			14,265			48,395	48,229
Net income attributable to Hawaiian Electric	62,553			63,886			185,207	193,062
Preferred stock dividends of Hawaiian Electric	471			471			1,417	1,417
Net income for common stock	62,082	$ 52,541	$ 69,167	63,415	$ 63,872	$ 64,358	183,790	191,645
Total assets	16,264,868						16,264,868		$ 15,822,637
Revenues from external customers
Segment financial information
Revenues	1,042,197			756,904			2,722,872	2,080,107
Intersegment revenues (eliminations)
Segment financial information
Revenues	0			0			0	0
Electric utility
Segment financial information
Revenues	955,971			679,499			2,483,636	1,846,242
Income (loss) before income taxes	63,712			61,175			179,771	170,163
Income taxes (benefit)	13,450			10,335			37,967	33,066
Net income attributable to Hawaiian Electric	50,262			50,840			141,804	137,097
Preferred stock dividends of Hawaiian Electric	498			498			1,496	1,496
Net income for common stock	49,764			50,342			140,308	135,601
Total assets	6,806,546						6,806,546		6,491,625
Electric utility | Revenues from external customers
Segment financial information
Revenues	955,971			679,482			2,483,632	1,846,206
Electric utility | Intersegment revenues (eliminations)
Segment financial information
Revenues	0			17			4	36
Bank
Segment financial information
Revenues	81,411			76,208			231,850	230,599
Income (loss) before income taxes	27,281			25,241			79,605	102,335
Income taxes (benefit)	6,525			5,976			17,513	23,230
Net income attributable to Hawaiian Electric	20,756			19,265			62,092	79,105
Preferred stock dividends of Hawaiian Electric	0			0			0	0
Net income for common stock	20,756			19,265			62,092	79,105
Total assets	9,315,611						9,315,611		9,181,603
Bank | Revenues from external customers
Segment financial information
Revenues	81,411			76,208			231,850	230,599
Bank | Intersegment revenues (eliminations)
Segment financial information
Revenues	0			0			0	0
Other
Segment financial information
Revenues	4,815			1,197			7,386	3,266
Income (loss) before income taxes	(11,088)			(8,265)			(25,774)	(31,207)
Income taxes (benefit)	(2,623)			(2,046)			(7,085)	(8,067)
Net income attributable to Hawaiian Electric	(8,465)			(6,219)			(18,689)	(23,140)
Preferred stock dividends of Hawaiian Electric	(27)			(27)			(79)	(79)
Net income for common stock	(8,438)			(6,192)			(18,610)	(23,061)
Total assets	142,711						142,711		$ 149,409
Other | Revenues from external customers
Segment financial information
Revenues	4,815			1,214			7,390	3,302
Other | Intersegment revenues (eliminations)
Segment financial information
Revenues	$ 0			$ (17)			$ (4)	$ (36)