Electric utility segment - Condensed consolidating balance sheet (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022	Mar. 31, 2022	Dec. 31, 2021
Utility property, plant and equipment
Total property, plant and equipment, net	$ 5,778,571	$ 5,687,003
Current assets
Cash and cash equivalents	315,334	199,877	$ 301,704
Other long-term assets
Operating lease right-of-use assets	110,920	115,684
Total assets	16,443,785	16,284,244
Capitalization
Common stock equity	2,237,955	2,202,499	2,303,642	$ 2,390,884
Preferred stock of subsidiaries - not subject to mandatory redemption	34,293	34,293
Current liabilities
Interest and preferred dividends payable	41,382	21,333
Deferred credits and other liabilities
Deferred income taxes	273,081	262,462
Total liabilities and shareholders’ equity	16,443,785	16,284,244
Hawaiian Electric Consolidated
Utility property, plant and equipment
Land	52,060	52,060
Plant and equipment	8,042,892	7,979,510
Finance lease right-of-use assets	88,297	48,371
Less accumulated depreciation	(3,133,811)	(3,086,499)
Construction in progress	315,862	275,353
Utility property, plant and equipment, net	5,365,300	5,268,795
Nonutility property, plant and equipment, less accumulated depreciation	6,945	6,945
Total property, plant and equipment, net	5,372,245	5,275,740
Investment in wholly owned subsidiaries, at equity	0	0
Current assets
Cash and cash equivalents	116,022	39,242	29,055
Advances to affiliates		0
Customer accounts receivable, net	235,305	288,338
Accrued unbilled revenues, net	160,532	183,280
Other accounts receivable, net	11,427	13,567
Fuel oil stock, at average cost	157,583	191,530
Materials and supplies, at average cost	84,093	79,568
Prepayments and other	43,909	33,482
Regulatory assets	64,973	52,273
Total current assets	873,844	881,280
Other long-term assets
Operating lease right-of-use assets	84,930	89,318
Regulatory assets	182,929	190,240
Other	160,515	160,889
Total other long-term assets	428,374	440,447
Total assets	6,674,463	6,597,467
Capitalization
Common stock equity	2,358,884	2,344,170	2,276,884	2,261,899
Preferred stock of subsidiaries - not subject to mandatory redemption	34,293	34,293
Long-term debt, net	1,734,347	1,584,854
Total capitalization	4,127,524	3,963,317
Current liabilities
Current portion of operating lease liabilities	18,414	19,095
Current portion of long-term debt	99,973	99,962
Short-term borrowings from affiliate		0
Accounts payable	191,769	202,492
Interest and preferred dividends payable	29,367	17,176
Taxes accrued, including revenue taxes	246,914	289,902
Regulatory liabilities	25,234	31,475
Other	86,580	85,596
Total current liabilities	698,251	833,665
Deferred credits and other liabilities
Operating lease liabilities	74,633	78,715
Finance lease liabilities	84,341	46,048
Deferred income taxes	384,953	384,430
Regulatory liabilities	1,044,317	1,024,175
Unamortized tax credits	93,445	95,300
Defined benefit pension and other postretirement benefit plans liability	49,388	49,748
Other	117,611	122,069
Total deferred credits and other liabilities	1,848,688	1,800,485
Total liabilities and shareholders’ equity	6,674,463	6,597,467
Hawaiian Electric Consolidated | Reportable Legal Entities | Hawaiian Electric (parent only)
Utility property, plant and equipment
Land	42,860	42,860
Plant and equipment	5,302,293	5,260,685
Finance lease right-of-use assets	88,297	48,371
Less accumulated depreciation	(1,889,007)	(1,855,150)
Construction in progress	248,788	215,560
Utility property, plant and equipment, net	3,793,231	3,712,326
Nonutility property, plant and equipment, less accumulated depreciation	5,298	5,298
Total property, plant and equipment, net	3,798,529	3,717,624
Investment in wholly owned subsidiaries, at equity	705,212	701,833
Current assets
Cash and cash equivalents	49,393	27,579	19,894
Advances to affiliates		0
Customer accounts receivable, net	172,426	216,802
Accrued unbilled revenues, net	118,035	136,508
Other accounts receivable, net	22,376	23,746
Fuel oil stock, at average cost	116,295	153,342
Materials and supplies, at average cost	50,744	48,130
Prepayments and other	33,369	24,040
Regulatory assets	58,943	46,504
Total current assets	621,581	676,651
Other long-term assets
Operating lease right-of-use assets	40,724	42,752
Regulatory assets	151,684	154,040
Other	113,888	115,028
Total other long-term assets	306,296	311,820
Total assets	5,431,618	5,407,928
Capitalization
Common stock equity	2,358,884	2,344,170	2,276,884	2,261,899
Preferred stock of subsidiaries - not subject to mandatory redemption	22,293	22,293
Long-term debt, net	1,226,587	1,126,915
Total capitalization	3,607,764	3,493,378
Current liabilities
Current portion of operating lease liabilities	8,955	9,775
Current portion of long-term debt	49,987	49,981
Short-term borrowings from affiliate		26,200
Accounts payable	146,125	143,253
Interest and preferred dividends payable	20,788	12,398
Taxes accrued, including revenue taxes	178,418	207,798
Regulatory liabilities	9,505	13,145
Other	61,360	64,659
Total current liabilities	475,138	615,176
Deferred credits and other liabilities
Operating lease liabilities	39,387	41,049
Finance lease liabilities	84,341	46,048
Deferred income taxes	271,588	271,234
Regulatory liabilities	745,894	729,683
Unamortized tax credits	68,123	69,614
Defined benefit pension and other postretirement benefit plans liability	65,917	65,907
Other	73,466	75,839
Total deferred credits and other liabilities	1,348,716	1,299,374
Total liabilities and shareholders’ equity	5,431,618	5,407,928
Hawaiian Electric Consolidated | Reportable Legal Entities | Hawaii Electric Light
Utility property, plant and equipment
Land	5,606	5,606
Plant and equipment	1,431,852	1,425,442
Finance lease right-of-use assets	0	0
Less accumulated depreciation	(651,463)	(644,457)
Construction in progress	28,136	23,989
Utility property, plant and equipment, net	814,131	810,580
Nonutility property, plant and equipment, less accumulated depreciation	115	115
Total property, plant and equipment, net	814,246	810,695
Investment in wholly owned subsidiaries, at equity	0	0
Current assets
Cash and cash equivalents	28,006	5,092	6,017
Advances to affiliates		4,500
Customer accounts receivable, net	34,224	39,339
Accrued unbilled revenues, net	21,831	23,839
Other accounts receivable, net	3,883	5,519
Fuel oil stock, at average cost	16,678	16,964
Materials and supplies, at average cost	10,578	9,783
Prepayments and other	5,025	6,346
Regulatory assets	2,575	2,435
Total current assets	122,800	113,817
Other long-term assets
Operating lease right-of-use assets	32,599	34,283
Regulatory assets	19,041	21,816
Other	32,786	32,654
Total other long-term assets	84,426	88,753
Total assets	1,021,472	1,013,265
Capitalization
Common stock equity	346,629	344,720	336,177	332,900
Preferred stock of subsidiaries - not subject to mandatory redemption	7,000	7,000
Long-term debt, net	249,346	224,439
Total capitalization	602,975	576,159
Current liabilities
Current portion of operating lease liabilities	6,780	6,690
Current portion of long-term debt	19,994	19,992
Short-term borrowings from affiliate		0
Accounts payable	20,957	32,113
Interest and preferred dividends payable	3,839	2,576
Taxes accrued, including revenue taxes	34,570	42,436
Regulatory liabilities	7,918	8,553
Other	21,072	20,856
Total current liabilities	115,130	133,216
Deferred credits and other liabilities
Operating lease liabilities	26,087	27,817
Finance lease liabilities	0	0
Deferred income taxes	50,657	50,615
Regulatory liabilities	195,238	194,222
Unamortized tax credits	12,903	13,150
Defined benefit pension and other postretirement benefit plans liability	0	129
Other	18,482	17,957
Total deferred credits and other liabilities	303,367	303,890
Total liabilities and shareholders’ equity	1,021,472	1,013,265
Hawaiian Electric Consolidated | Reportable Legal Entities | Maui Electric
Utility property, plant and equipment
Land	3,594	3,594
Plant and equipment	1,308,747	1,293,383
Finance lease right-of-use assets	0	0
Less accumulated depreciation	(593,341)	(586,892)
Construction in progress	38,938	35,804
Utility property, plant and equipment, net	757,938	745,889
Nonutility property, plant and equipment, less accumulated depreciation	1,532	1,532
Total property, plant and equipment, net	759,470	747,421
Investment in wholly owned subsidiaries, at equity	0	0
Current assets
Cash and cash equivalents	38,546	6,494	3,067
Advances to affiliates		21,700
Customer accounts receivable, net	28,655	32,197
Accrued unbilled revenues, net	20,666	22,933
Other accounts receivable, net	4,677	6,686
Fuel oil stock, at average cost	24,610	21,224
Materials and supplies, at average cost	22,771	21,655
Prepayments and other	5,515	4,137
Regulatory assets	3,455	3,334
Total current assets	148,895	140,360
Other long-term assets
Operating lease right-of-use assets	11,607	12,283
Regulatory assets	12,204	14,384
Other	30,402	29,495
Total other long-term assets	54,213	56,162
Total assets	962,578	943,943
Capitalization
Common stock equity	358,506	357,036	345,744	343,260
Preferred stock of subsidiaries - not subject to mandatory redemption	5,000	5,000
Long-term debt, net	258,414	233,500
Total capitalization	621,920	595,536
Current liabilities
Current portion of operating lease liabilities	2,679	2,630
Current portion of long-term debt	29,992	29,989
Short-term borrowings from affiliate		0
Accounts payable	24,687	27,126
Interest and preferred dividends payable	4,740	2,282
Taxes accrued, including revenue taxes	33,926	40,709
Regulatory liabilities	7,811	9,777
Other	23,657	22,385
Total current liabilities	127,492	134,898
Deferred credits and other liabilities
Operating lease liabilities	9,159	9,849
Finance lease liabilities	0	0
Deferred income taxes	62,708	62,581
Regulatory liabilities	103,185	100,270
Unamortized tax credits	12,419	12,536
Defined benefit pension and other postretirement benefit plans liability	0	0
Other	25,695	28,273
Total deferred credits and other liabilities	213,166	213,509
Total liabilities and shareholders’ equity	962,578	943,943
Hawaiian Electric Consolidated | Reportable Legal Entities | Other subsidiaries
Utility property, plant and equipment
Land	0	0
Plant and equipment	0	0
Finance lease right-of-use assets	0	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
Advances to affiliates		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 affiliate		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	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
Finance lease right-of-use assets	0	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	(705,212)	(701,833)
Current assets
Cash and cash equivalents	0	0	0
Advances to affiliates		(26,200)
Customer accounts receivable, net	0	0
Accrued unbilled revenues, net	0	0
Other accounts receivable, net	(19,509)	(22,384)
Fuel oil stock, at average cost	0	0
Materials and supplies, at average cost	0	0
Prepayments and other	0	(1,041)
Regulatory assets	0	0
Total current assets	(19,509)	(49,625)
Other long-term assets
Operating lease right-of-use assets	0	0
Regulatory assets	0	0
Other	(16,561)	(16,288)
Total other long-term assets	(16,561)	(16,288)
Total assets	(741,282)	(767,746)
Capitalization
Common stock equity	(705,212)	(701,833)	$ (681,998)	$ (676,237)
Preferred stock of subsidiaries - not subject to mandatory redemption	0	0
Long-term debt, net	0	0
Total capitalization	(705,212)	(701,833)
Current liabilities
Current portion of operating lease liabilities	0	0
Current portion of long-term debt	0	0
Short-term borrowings from affiliate		(26,200)
Accounts payable	0	0
Interest and preferred dividends payable	0	(80)
Taxes accrued, including revenue taxes	0	(1,041)
Regulatory liabilities	0	0
Other	(19,509)	(22,304)
Total current liabilities	(19,509)	(49,625)
Deferred credits and other liabilities
Operating lease liabilities	0	0
Finance lease liabilities	0	0
Deferred income taxes	0	0
Regulatory liabilities	0	0
Unamortized tax credits	0	0
Defined benefit pension and other postretirement benefit plans liability	(16,529)	(16,288)
Other	(32)	0
Total deferred credits and other liabilities	(16,561)	(16,288)
Total liabilities and shareholders’ equity	$ (741,282)	$ (767,746)