Electric utility segment - Consolidating Balance Sheet (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Utility property, plant and equipment
Finance lease right-of-use assets	$ 49,370	$ 0
Total property, plant and equipment, net	5,687,003	5,392,068
Current assets
Cash and cash equivalents	199,877	305,551	$ 341,421
Restricted cash	5,100	5,900
Other long-term assets
Operating lease right-of-use-assets	115,684	122,416
Total assets	16,284,244	15,822,637	15,004,007
Capitalization
Total shareholders’ equity	2,202,499	2,390,884	2,337,502	$ 2,280,260
Cumulative preferred stock – not subject to mandatory redemption	34,293	34,293
Current liabilities
Interest and dividends payable	21,333	19,889
Deferred credits and other liabilities
Deferred income taxes	262,462	384,760
Total capitalization and liabilities	16,284,244	15,822,637
Hawaiian Electric (parent only)
Utility property, plant and equipment
Total property, plant and equipment, net	1,877	2,052
Other long-term assets
Total assets	2,929,232	3,062,073
Capitalization
Total shareholders’ equity	2,202,499	2,390,884
Current liabilities
Short-term borrowings from non-affiliate	34,918	0
Deferred credits and other liabilities
Total capitalization and liabilities	2,929,232	3,062,073
Hawaiian Electric Company, Inc. and Subsidiaries
Utility property, plant and equipment
Land	52,060	51,937
Plant and equipment	7,979,510	7,735,983
Finance lease right-of-use assets	48,371	0
Less accumulated depreciation	(3,086,499)	(2,940,517)
Construction in progress	275,353	204,569
Utility property, plant and equipment, net	5,268,795	5,051,972
Nonutility property, plant and equipment, less accumulated depreciation	6,945	6,949
Total property, plant and equipment, net	5,275,740	5,058,921
Investment in wholly-owned subsidiaries, at equity	0	0
Current assets
Cash and cash equivalents	39,242	52,169	47,360
Restricted cash	0	3,089
Advances to affiliates	0	0
Customer accounts receivable, net	288,338	186,859
Accrued unbilled revenues, net	183,280	129,155
Other accounts receivable, net	13,567	7,267
Fuel oil stock, at average cost	191,530	104,078
Materials and supplies, at average cost	79,568	71,877
Prepayments and other	33,482	46,031
Regulatory assets	52,273	66,664
Total current assets	881,280	667,189
Other long-term assets
Operating lease right-of-use-assets	89,318	101,470
Regulatory assets	190,240	498,879
Other	160,889	165,166
Total other long-term assets	440,447	765,515
Total assets	6,597,467	6,491,625
Capitalization
Total shareholders’ equity	2,344,170	2,261,899	2,141,918	2,047,352
Cumulative preferred stock – not subject to mandatory redemption	34,293	34,293
Long-term debt, net	1,584,854	1,624,427
Total capitalization	3,963,317	3,920,619
Current liabilities
Current portion of operating lease liabilities	19,095	49,368
Current portion of long-term debt, net	99,962	51,975
Short-term borrowings from non-affiliate	87,967	0
Short-term borrowings-affiliate	0	0
Accounts payable	202,492	160,007
Interest and dividends payable	17,176	17,325
Taxes accrued, including revenue taxes	289,902	208,280
Regulatory liabilities	31,475	29,760
Other	85,596	71,569
Total current liabilities	833,665	588,284
Deferred credits and other liabilities
Operating lease liabilities	78,715	65,780
Finance lease liabilities	46,048	0
Deferred income taxes	384,430	408,634
Regulatory liabilities	1,024,175	967,008
Unamortized tax credits	95,300	103,945
Defined benefit pension and other postretirement benefit plans liability	49,748	321,780
Other	122,069	115,575
Total deferred credits and other liabilities	1,800,485	1,982,722
Total capitalization and liabilities	6,597,467	6,491,625
Hawaiian Electric Company, Inc. and Subsidiaries | Reportable Legal Entities | Hawaiian Electric (parent only)
Utility property, plant and equipment
Land	42,860	42,737
Plant and equipment	5,260,685	5,097,033
Finance lease right-of-use assets	48,371
Less accumulated depreciation	(1,855,150)	(1,757,096)
Construction in progress	215,560	159,854
Utility property, plant and equipment, net	3,712,326	3,542,528
Nonutility property, plant and equipment, less accumulated depreciation	5,298	5,302
Total property, plant and equipment, net	3,717,624	3,547,830
Investment in wholly-owned subsidiaries, at equity	701,833	676,237
Current assets
Cash and cash equivalents	27,579	23,344	42,205
Restricted cash		3,089
Advances to affiliates	0	1,000
Customer accounts receivable, net	216,802	135,949
Accrued unbilled revenues, net	136,508	92,469
Other accounts receivable, net	23,746	18,624
Fuel oil stock, at average cost	153,342	71,184
Materials and supplies, at average cost	48,130	42,006
Prepayments and other	24,040	32,140
Regulatory assets	46,504	58,695
Total current assets	676,651	478,500
Other long-term assets
Operating lease right-of-use-assets	42,752	78,710
Regulatory assets	154,040	337,903
Other	115,028	130,546
Total other long-term assets	311,820	547,159
Total assets	5,407,928	5,249,726
Capitalization
Total shareholders’ equity	2,344,170	2,261,899	2,141,918	2,047,352
Cumulative preferred stock – not subject to mandatory redemption	22,293	22,293
Long-term debt, net	1,126,915	1,136,620
Total capitalization	3,493,378	3,420,812
Current liabilities
Current portion of operating lease liabilities	9,775	45,955
Current portion of long-term debt, net	49,981	39,981
Short-term borrowings from non-affiliate	87,967
Short-term borrowings-affiliate	26,200	0
Accounts payable	143,253	111,024
Interest and dividends payable	12,398	12,442
Taxes accrued, including revenue taxes	207,798	143,723
Regulatory liabilities	13,145	22,240
Other	64,659	56,752
Total current liabilities	615,176	432,117
Deferred credits and other liabilities
Operating lease liabilities	41,049	46,426
Finance lease liabilities	46,048
Deferred income taxes	271,234	291,027
Regulatory liabilities	729,683	695,152
Unamortized tax credits	69,614	76,201
Defined benefit pension and other postretirement benefit plans liability	65,907	220,480
Other	75,839	67,511
Total deferred credits and other liabilities	1,299,374	1,396,797
Total capitalization and liabilities	5,407,928	5,249,726
Hawaiian Electric Company, Inc. and Subsidiaries | Reportable Legal Entities | Hawaii Electric Light
Utility property, plant and equipment
Land	5,606	5,606
Plant and equipment	1,425,442	1,390,361
Finance lease right-of-use assets	0
Less accumulated depreciation	(644,457)	(619,991)
Construction in progress	23,989	17,129
Utility property, plant and equipment, net	810,580	793,105
Nonutility property, plant and equipment, less accumulated depreciation	115	115
Total property, plant and equipment, net	810,695	793,220
Investment in wholly-owned subsidiaries, at equity	0	0
Current assets
Cash and cash equivalents	5,092	5,326	3,046
Restricted cash		0
Advances to affiliates	4,500	0
Customer accounts receivable, net	39,339	28,469
Accrued unbilled revenues, net	23,839	19,529
Other accounts receivable, net	5,519	3,347
Fuel oil stock, at average cost	16,964	12,814
Materials and supplies, at average cost	9,783	9,727
Prepayments and other	6,346	6,052
Regulatory assets	2,435	3,051
Total current assets	113,817	88,315
Other long-term assets
Operating lease right-of-use-assets	34,283	22,442
Regulatory assets	21,816	81,645
Other	32,654	17,124
Total other long-term assets	88,753	121,211
Total assets	1,013,265	1,002,746
Capitalization
Total shareholders’ equity	344,720	332,900	317,451	298,998
Cumulative preferred stock – not subject to mandatory redemption	7,000	7,000
Long-term debt, net	224,439	234,390
Total capitalization	576,159	574,290
Current liabilities
Current portion of operating lease liabilities	6,690	3,378
Current portion of long-term debt, net	19,992	11,994
Short-term borrowings from non-affiliate	0
Short-term borrowings-affiliate	0	1,000
Accounts payable	32,113	26,139
Interest and dividends payable	2,576	2,617
Taxes accrued, including revenue taxes	42,436	33,153
Regulatory liabilities	8,553	3,247
Other	20,856	14,158
Total current liabilities	133,216	95,686
Deferred credits and other liabilities
Operating lease liabilities	27,817	19,063
Finance lease liabilities	0
Deferred income taxes	50,615	53,298
Regulatory liabilities	194,222	179,267
Unamortized tax credits	13,150	14,212
Defined benefit pension and other postretirement benefit plans liability	129	48,900
Other	17,957	18,030
Total deferred credits and other liabilities	303,890	332,770
Total capitalization and liabilities	1,013,265	1,002,746
Hawaiian Electric Company, Inc. and Subsidiaries | Reportable Legal Entities | Maui Electric
Utility property, plant and equipment
Land	3,594	3,594
Plant and equipment	1,293,383	1,248,589
Finance lease right-of-use assets	0
Less accumulated depreciation	(586,892)	(563,430)
Construction in progress	35,804	27,586
Utility property, plant and equipment, net	745,889	716,339
Nonutility property, plant and equipment, less accumulated depreciation	1,532	1,532
Total property, plant and equipment, net	747,421	717,871
Investment in wholly-owned subsidiaries, at equity	0	0
Current assets
Cash and cash equivalents	6,494	23,422	2,032
Restricted cash		0
Advances to affiliates	21,700	0
Customer accounts receivable, net	32,197	22,441
Accrued unbilled revenues, net	22,933	17,157
Other accounts receivable, net	6,686	3,031
Fuel oil stock, at average cost	21,224	20,080
Materials and supplies, at average cost	21,655	20,144
Prepayments and other	4,137	7,114
Regulatory assets	3,334	4,918
Total current assets	140,360	118,307
Other long-term assets
Operating lease right-of-use-assets	12,283	318
Regulatory assets	14,384	79,331
Other	29,495	18,510
Total other long-term assets	56,162	98,159
Total assets	943,943	934,337
Capitalization
Total shareholders’ equity	357,036	343,260	309,363	292,870
Cumulative preferred stock – not subject to mandatory redemption	5,000	5,000
Long-term debt, net	233,500	253,417
Total capitalization	595,536	601,677
Current liabilities
Current portion of operating lease liabilities	2,630	35
Current portion of long-term debt, net	29,989	0
Short-term borrowings from non-affiliate	0
Short-term borrowings-affiliate	0	0
Accounts payable	27,126	22,844
Interest and dividends payable	2,282	2,269
Taxes accrued, including revenue taxes	40,709	30,679
Regulatory liabilities	9,777	4,273
Other	22,385	18,540
Total current liabilities	134,898	78,640
Deferred credits and other liabilities
Operating lease liabilities	9,849	291
Finance lease liabilities	0
Deferred income taxes	62,581	64,309
Regulatory liabilities	100,270	92,589
Unamortized tax credits	12,536	13,532
Defined benefit pension and other postretirement benefit plans liability	0	53,257
Other	28,273	30,042
Total deferred credits and other liabilities	213,509	254,020
Total capitalization and liabilities	943,943	934,337
Hawaiian Electric Company, Inc. and Subsidiaries | 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
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
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
Total shareholders’ equity	77	77	77	101
Cumulative preferred stock – 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, net	0	0
Short-term borrowings from non-affiliate	0
Short-term borrowings-affiliate	0	0
Accounts payable	0	0
Interest and 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 capitalization and liabilities	77	77
Hawaiian Electric Company, Inc. and Subsidiaries | Consolidating adjustments
Utility property, plant and equipment
Land	0	0
Plant and equipment	0	0
Finance lease right-of-use assets	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	(701,833)	(676,237)
Current assets
Cash and cash equivalents	0	0	0
Restricted cash		0
Advances to affiliates	(26,200)	(1,000)
Customer accounts receivable, net	0	0
Accrued unbilled revenues, net	0	0
Other accounts receivable, net	(22,384)	(17,735)
Fuel oil stock, at average cost	0	0
Materials and supplies, at average cost	0	0
Prepayments and other	(1,041)	725
Regulatory assets	0	0
Total current assets	(49,625)	(18,010)
Other long-term assets
Operating lease right-of-use-assets	0	0
Regulatory assets	0	0
Other	(16,288)	(1,014)
Total other long-term assets	(16,288)	(1,014)
Total assets	(767,746)	(695,261)
Capitalization
Total shareholders’ equity	(701,833)	(676,237)	$ (626,891)	$ (591,969)
Cumulative preferred stock – not subject to mandatory redemption	0	0
Long-term debt, net	0	0
Total capitalization	(701,833)	(676,237)
Current liabilities
Current portion of operating lease liabilities	0	0
Current portion of long-term debt, net	0	0
Short-term borrowings from non-affiliate	0
Short-term borrowings-affiliate	(26,200)	(1,000)
Accounts payable	0	0
Interest and dividends payable	(80)	(3)
Taxes accrued, including revenue taxes	(1,041)	725
Regulatory liabilities	0	0
Other	(22,304)	(17,881)
Total current liabilities	(49,625)	(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	(16,288)	(857)
Other	0	(8)
Total deferred credits and other liabilities	(16,288)	(865)
Total capitalization and liabilities	$ (767,746)	$ (695,261)