Electric utility segment - Condensed consolidating balance sheet (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Dec. 31, 2021	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020
Utility property, plant and equipment
Total property, plant and equipment, net	$ 5,599,937			$ 5,392,068
Current assets
Cash and cash equivalents	175,280			305,551	$ 227,923
Restricted cash	3,898			5,911	9,412
Other long-term assets
Operating lease right-of-use assets	121,302			122,416
Total assets	16,264,868			15,822,637
Capitalization
Common stock equity	2,162,922	$ 2,233,504	$ 2,303,642	2,390,884	2,383,543	$ 2,367,329	$ 2,321,293	$ 2,337,502
Preferred stock of subsidiaries - not subject to mandatory redemption	34,293			34,293
Current liabilities
Interest and preferred dividends payable	36,158			19,889
Deferred credits and other liabilities
Deferred income taxes	263,929			384,760
Total liabilities and shareholders’ equity	16,264,868			15,822,637
Hawaiian Electric Consolidated
Utility property, plant and equipment
Land	52,060			51,937
Plant and equipment	7,890,926			7,735,983
Right-of-use assets - finance lease	48,371			0
Less accumulated depreciation	(3,067,642)			(2,940,517)
Construction in progress	257,582			204,569
Utility property, plant and equipment, net	5,181,297			5,051,972
Nonutility property, plant and equipment, less accumulated depreciation	6,946			6,949
Total property, plant and equipment, net	5,188,243			5,058,921
Investment in wholly owned subsidiaries, at equity	0			0
Current assets
Cash and cash equivalents	21,304			52,169	36,467
Restricted cash	0			3,089	6,313
Advances to affiliates	0			0
Customer accounts receivable, net	258,972			186,859
Accrued unbilled revenues, net	220,420			129,155
Other accounts receivable, net	15,492			7,267
Fuel oil stock, at average cost	229,725			104,078
Materials and supplies, at average cost	77,579			71,877
Prepayments and other	45,798			46,031
Regulatory assets	55,906			66,664
Total current assets	925,196			667,189
Other long-term assets
Operating lease right-of-use assets	93,709			101,470
Regulatory assets	441,282			498,879
Other	158,116			165,166
Total other long-term assets	693,107			765,515
Total assets	6,806,546			6,491,625
Capitalization
Common stock equity	2,307,992	$ 2,289,595	$ 2,276,884	2,261,899	2,193,919	$ 2,171,396	$ 2,157,385	2,141,918
Preferred stock of subsidiaries - not subject to mandatory redemption	34,293			34,293
Long-term debt, net	1,684,699			1,624,427
Total capitalization	4,026,984			3,920,619
Current liabilities
Current portion of operating lease liabilities	18,572			49,368
Current portion of long-term debt	51,995			51,975
Short-term borrowings from non-affiliates	97,450			0
Short-term borrowings from affiliate	0			0
Accounts payable	165,461			160,007
Interest and preferred dividends payable	29,164			17,325
Taxes accrued, including revenue taxes	256,343			208,280
Regulatory liabilities	29,318			29,760
Other	79,788			71,569
Total current liabilities	728,091			588,284
Deferred credits and other liabilities
Operating lease liabilities	83,311			65,780
Finance lease liabilities	46,468			0
Deferred income taxes	392,176			408,634
Regulatory liabilities	1,001,058			967,008
Unamortized tax credits	98,001			103,945
Defined benefit pension and other postretirement benefit plans liability	308,133			321,780
Other	122,324			115,575
Total deferred credits and other liabilities	2,051,471			1,982,722
Total liabilities and shareholders’ equity	6,806,546			6,491,625
Hawaiian Electric Consolidated | Reportable Legal Entities | Hawaiian Electric
Utility property, plant and equipment
Land	42,860			42,737
Plant and equipment	5,218,701			5,097,033
Right-of-use assets - finance lease	48,371
Less accumulated depreciation	(1,845,767)			(1,757,096)
Construction in progress	197,033			159,854
Utility property, plant and equipment, net	3,661,198			3,542,528
Nonutility property, plant and equipment, less accumulated depreciation	5,300			5,302
Total property, plant and equipment, net	3,666,498			3,547,830
Investment in wholly owned subsidiaries, at equity	689,016			676,237
Current assets
Cash and cash equivalents	13,295			23,344	25,981
Restricted cash				3,089	6,313
Advances to affiliates	0			1,000
Customer accounts receivable, net	181,813			135,949
Accrued unbilled revenues, net	167,037			92,469
Other accounts receivable, net	26,795			18,624
Fuel oil stock, at average cost	184,981			71,184
Materials and supplies, at average cost	45,405			42,006
Prepayments and other	33,628			32,140
Regulatory assets	50,074			58,695
Total current assets	703,028			478,500
Other long-term assets
Operating lease right-of-use assets	44,802			78,710
Regulatory assets	298,759			337,903
Other	119,348			130,546
Total other long-term assets	462,909			547,159
Total assets	5,521,451			5,249,726
Capitalization
Common stock equity	2,307,992			2,261,899	2,193,919			2,141,918
Preferred stock of subsidiaries - not subject to mandatory redemption	22,293			22,293
Long-term debt, net	1,176,814			1,136,620
Total capitalization	3,507,099			3,420,812
Current liabilities
Current portion of operating lease liabilities	9,371			45,955
Current portion of long-term debt	39,996			39,981
Short-term borrowings from non-affiliates	97,450
Short-term borrowings from affiliate	17,500			0
Accounts payable	117,259			111,024
Interest and preferred dividends payable	20,800			12,442
Taxes accrued, including revenue taxes	181,935			143,723
Regulatory liabilities	15,349			22,240
Other	62,303			56,752
Total current liabilities	561,963			432,117
Deferred credits and other liabilities
Operating lease liabilities	43,275			46,426
Finance lease liabilities	46,468
Deferred income taxes	278,230			291,027
Regulatory liabilities	725,346			695,152
Unamortized tax credits	71,916			76,201
Defined benefit pension and other postretirement benefit plans liability	211,560			220,480
Other	75,594			67,511
Total deferred credits and other liabilities	1,452,389			1,396,797
Total liabilities and shareholders’ equity	5,521,451			5,249,726
Hawaiian Electric Consolidated | Reportable Legal Entities | Hawaii Electric Light
Utility property, plant and equipment
Land	5,606			5,606
Plant and equipment	1,403,784			1,390,361
Right-of-use assets - finance lease	0
Less accumulated depreciation	(640,257)			(619,991)
Construction in progress	25,671			17,129
Utility property, plant and equipment, net	794,804			793,105
Nonutility property, plant and equipment, less accumulated depreciation	114			115
Total property, plant and equipment, net	794,918			793,220
Investment in wholly owned subsidiaries, at equity	0			0
Current assets
Cash and cash equivalents	5,154			5,326	3,788
Restricted cash				0	0
Advances to affiliates	1,500			0
Customer accounts receivable, net	40,566			28,469
Accrued unbilled revenues, net	26,508			19,529
Other accounts receivable, net	4,615			3,347
Fuel oil stock, at average cost	20,817			12,814
Materials and supplies, at average cost	10,621			9,727
Prepayments and other	6,731			6,052
Regulatory assets	2,397			3,051
Total current assets	118,909			88,315
Other long-term assets
Operating lease right-of-use assets	35,953			22,442
Regulatory assets	73,845			81,645
Other	18,831			17,124
Total other long-term assets	128,629			121,211
Total assets	1,042,456			1,002,746
Capitalization
Common stock equity	338,598			332,900	323,691			317,451
Preferred stock of subsidiaries - not subject to mandatory redemption	7,000			7,000
Long-term debt, net	244,417			234,390
Total capitalization	590,015			574,290
Current liabilities
Current portion of operating lease liabilities	6,611			3,378
Current portion of long-term debt	11,999			11,994
Short-term borrowings from non-affiliates	0
Short-term borrowings from affiliate	0			1,000
Accounts payable	26,043			26,139
Interest and preferred dividends payable	3,822			2,617
Taxes accrued, including revenue taxes	39,023			33,153
Regulatory liabilities	6,451			3,247
Other	18,022			14,158
Total current liabilities	111,971			95,686
Deferred credits and other liabilities
Operating lease liabilities	29,517			19,063
Finance lease liabilities	0
Deferred income taxes	50,774			53,298
Regulatory liabilities	183,073			179,267
Unamortized tax credits	13,354			14,212
Defined benefit pension and other postretirement benefit plans liability	46,584			48,900
Other	17,168			18,030
Total deferred credits and other liabilities	340,470			332,770
Total liabilities and shareholders’ equity	1,042,456			1,002,746
Hawaiian Electric Consolidated | Reportable Legal Entities | Maui Electric
Utility property, plant and equipment
Land	3,594			3,594
Plant and equipment	1,268,441			1,248,589
Right-of-use assets - finance lease	0
Less accumulated depreciation	(581,618)			(563,430)
Construction in progress	34,878			27,586
Utility property, plant and equipment, net	725,295			716,339
Nonutility property, plant and equipment, less accumulated depreciation	1,532			1,532
Total property, plant and equipment, net	726,827			717,871
Investment in wholly owned subsidiaries, at equity	0			0
Current assets
Cash and cash equivalents	2,778			23,422	6,621
Restricted cash				0	0
Advances to affiliates	16,000			0
Customer accounts receivable, net	36,593			22,441
Accrued unbilled revenues, net	26,875			17,157
Other accounts receivable, net	4,691			3,031
Fuel oil stock, at average cost	23,927			20,080
Materials and supplies, at average cost	21,553			20,144
Prepayments and other	6,611			7,114
Regulatory assets	3,435			4,918
Total current assets	142,463			118,307
Other long-term assets
Operating lease right-of-use assets	12,954			318
Regulatory assets	68,678			79,331
Other	20,233			18,510
Total other long-term assets	101,865			98,159
Total assets	971,155			934,337
Capitalization
Common stock equity	350,341			343,260	316,132			309,363
Preferred stock of subsidiaries - not subject to mandatory redemption	5,000			5,000
Long-term debt, net	263,468			253,417
Total capitalization	618,809			601,677
Current liabilities
Current portion of operating lease liabilities	2,590			35
Current portion of long-term debt	0			0
Short-term borrowings from non-affiliates	0
Short-term borrowings from affiliate	0			0
Accounts payable	22,159			22,844
Interest and preferred dividends payable	4,583			2,269
Taxes accrued, including revenue taxes	36,557			30,679
Regulatory liabilities	7,518			4,273
Other	20,188			18,540
Total current liabilities	93,595			78,640
Deferred credits and other liabilities
Operating lease liabilities	10,519			291
Finance lease liabilities	0
Deferred income taxes	63,172			64,309
Regulatory liabilities	92,639			92,589
Unamortized tax credits	12,731			13,532
Defined benefit pension and other postretirement benefit plans liability	50,128			53,257
Other	29,562			30,042
Total deferred credits and other liabilities	258,751			254,020
Total liabilities and shareholders’ equity	971,155			934,337
Hawaiian Electric Consolidated | Reportable Legal Entities | Other subsidiaries
Utility property, plant and equipment
Land	0			0
Plant and equipment	0			0
Right-of-use assets - finance lease	0
Less accumulated depreciation	0			0
Construction in progress	0			0
Utility property, plant and equipment, net	0			0
Nonutility property, plant and equipment, less accumulated depreciation	0			0
Total property, plant and equipment, net	0			0
Investment in wholly owned subsidiaries, at equity	0			0
Current assets
Cash and cash equivalents	77			77	77
Restricted cash				0	0
Advances to affiliates	0			0
Customer accounts receivable, net	0			0
Accrued unbilled revenues, net	0			0
Other accounts receivable, net	0			0
Fuel oil stock, at average cost	0			0
Materials and supplies, at average cost	0			0
Prepayments and other	0			0
Regulatory assets	0			0
Total current assets	77			77
Other long-term assets
Operating lease right-of-use assets	0			0
Regulatory assets	0			0
Other	0			0
Total other long-term assets	0			0
Total assets	77			77
Capitalization
Common stock equity	77			77	77			77
Preferred stock of subsidiaries - not subject to mandatory redemption	0			0
Long-term debt, net	0			0
Total capitalization	77			77
Current liabilities
Current portion of operating lease liabilities	0			0
Current portion of long-term debt	0			0
Short-term borrowings from non-affiliates	0
Short-term borrowings from affiliate	0			0
Accounts payable	0			0
Interest and preferred dividends payable	0			0
Taxes accrued, including revenue taxes	0			0
Regulatory liabilities	0			0
Other	0			0
Total current liabilities	0			0
Deferred credits and other liabilities
Operating lease liabilities	0			0
Finance lease liabilities	0
Deferred income taxes	0			0
Regulatory liabilities	0			0
Unamortized tax credits	0			0
Defined benefit pension and other postretirement benefit plans liability	0			0
Other				0
Total deferred credits and other liabilities	0			0
Total liabilities and shareholders’ equity	77			77
Hawaiian Electric Consolidated | Consolidating adjustments
Utility property, plant and equipment
Land	0			0
Plant and equipment	0			0
Right-of-use assets - finance lease	0
Less accumulated depreciation	0			0
Construction in progress	0			0
Utility property, plant and equipment, net	0			0
Nonutility property, plant and equipment, less accumulated depreciation	0			0
Total property, plant and equipment, net	0			0
Investment in wholly owned subsidiaries, at equity	(689,016)			(676,237)
Current assets
Cash and cash equivalents	0			0	0
Restricted cash				0	0
Advances to affiliates	(17,500)			(1,000)
Customer accounts receivable, net	0			0
Accrued unbilled revenues, net	0			0
Other accounts receivable, net	(20,609)			(17,735)
Fuel oil stock, at average cost	0			0
Materials and supplies, at average cost	0			0
Prepayments and other	(1,172)			725
Regulatory assets	0			0
Total current assets	(39,281)			(18,010)
Other long-term assets
Operating lease right-of-use assets	0			0
Regulatory assets	0			0
Other	(296)			(1,014)
Total other long-term assets	(296)			(1,014)
Total assets	(728,593)			(695,261)
Capitalization
Common stock equity	(689,016)			(676,237)	$ (639,900)			$ (626,891)
Preferred stock of subsidiaries - not subject to mandatory redemption	0			0
Long-term debt, net	0			0
Total capitalization	(689,016)			(676,237)
Current liabilities
Current portion of operating lease liabilities	0			0
Current portion of long-term debt	0			0
Short-term borrowings from non-affiliates	0
Short-term borrowings from affiliate	(17,500)			(1,000)
Accounts payable	0			0
Interest and preferred dividends payable	(41)			(3)
Taxes accrued, including revenue taxes	(1,172)			725
Regulatory liabilities	0			0
Other	(20,725)			(17,881)
Total current liabilities	(39,438)			(18,159)
Deferred credits and other liabilities
Operating lease liabilities	0			0
Finance lease liabilities	0
Deferred income taxes	0			0
Regulatory liabilities	0			0
Unamortized tax credits	0			0
Defined benefit pension and other postretirement benefit plans liability	(139)			(857)
Other	0			(8)
Total deferred credits and other liabilities	(139)			(865)
Total liabilities and shareholders’ equity	$ (728,593)			$ (695,261)