Electric utility segment - Consolidating Statement of Income (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Condensed Income Statements, Captions [Line Items]
Revenues	$ 3,741,985	$ 2,850,379	$ 2,579,775
Expenses
Total expenses	3,360,912	2,464,313	2,268,282
Operating income	381,073	386,066	311,493
Allowance for equity funds used during construction	10,574	9,534	8,768
Retirement defined benefits credit (expense)—other than service costs	4,411	5,848	(3,210)
Allowance for borrowed funds used during construction	3,416	3,250	2,992
Income before income taxes	304,195	310,863	240,624
Income taxes	61,167	62,807	40,910
Net income	243,028	248,056	199,714
Preferred stock dividends of Hawaiian Electric	1,890	1,890	1,890
Net income for common stock	241,138	246,166	197,824
Hawaiian Electric (parent only)
Expenses
Total expenses	21,981	24,934	21,870
Retirement defined benefits credit (expense)—other than service costs	(147)	114	(634)
Income before income taxes	229,271	235,584	186,565
Income taxes	(11,867)	(10,582)	(11,259)
Net income for common stock	241,138	246,166	197,824
Hawaiian Electric Company, Inc. and Subsidiaries
Condensed Income Statements, Captions [Line Items]
Revenues	3,408,587	2,539,636	2,265,320
Expenses
Fuel oil	1,265,614	644,349	515,274
Purchased power	793,584	670,494	568,749
Other operation and maintenance	497,601	475,412	474,192
Depreciation	235,424	229,469	222,733
Taxes, other than income taxes	317,173	240,354	215,822
Total expenses	3,109,396	2,260,078	1,996,770
Operating income	299,191	279,558	268,550
Allowance for equity funds used during construction	10,574	9,534	8,768
Equity in earnings of subsidiaries	0	0	0
Retirement defined benefits credit (expense)—other than service costs	3,835	3,890	(763)
Interest expense and other charges, net	(76,416)	(72,447)	(67,794)
Allowance for borrowed funds used during construction	3,416	3,250	2,992
Income before income taxes	240,600	223,785	211,753
Income taxes	49,676	44,148	40,418
Net income (loss)	190,924	179,637	171,335
Preferred stock dividends of subsidiaries	915	915	915
Net income	190,009	178,722	170,420
Preferred stock dividends of Hawaiian Electric	1,080	1,080	1,080
Net income for common stock	188,929	177,642	169,340
Hawaiian Electric Company, Inc. and Subsidiaries | Reportable Legal Entities | Hawaiian Electric (parent only)
Condensed Income Statements, Captions [Line Items]
Revenues	2,452,969	1,793,372	1,608,305
Expenses
Fuel oil	917,801	442,818	354,087
Purchased power	601,235	508,642	446,672
Other operation and maintenance	326,785	313,009	311,781
Depreciation	158,725	155,607	151,387
Taxes, other than income taxes	228,843	170,604	154,191
Total expenses	2,233,389	1,590,680	1,418,118
Operating income	219,580	202,692	190,187
Allowance for equity funds used during construction	8,464	7,734	7,335
Equity in earnings of subsidiaries	47,493	45,353	47,504
Retirement defined benefits credit (expense)—other than service costs	3,296	3,348	(1,294)
Interest expense and other charges, net	(55,260)	(51,680)	(48,775)
Allowance for borrowed funds used during construction	2,769	2,617	2,540
Income before income taxes	226,342	210,064	197,497
Income taxes	36,333	31,342	27,077
Net income (loss)	190,009	178,722	170,420
Preferred stock dividends of subsidiaries	0	0	0
Net income	190,009	178,722	170,420
Preferred stock dividends of Hawaiian Electric	1,080	1,080	1,080
Net income for common stock	188,929	177,642	169,340
Hawaiian Electric Company, Inc. and Subsidiaries | Reportable Legal Entities | Hawaii Electric Light
Condensed Income Statements, Captions [Line Items]
Revenues	485,590	381,033	334,221
Expenses
Fuel oil	133,238	80,086	72,202
Purchased power	143,636	108,997	73,120
Other operation and maintenance	85,110	79,390	73,746
Depreciation	41,404	40,201	39,041
Taxes, other than income taxes	44,685	35,499	31,181
Total expenses	448,073	344,173	289,290
Operating income	37,517	36,860	44,931
Allowance for equity funds used during construction	898	586	543
Equity in earnings of subsidiaries	0	0	0
Retirement defined benefits credit (expense)—other than service costs	666	670	672
Interest expense and other charges, net	(10,659)	(10,353)	(10,004)
Allowance for borrowed funds used during construction	277	197	160
Income before income taxes	28,699	27,960	36,302
Income taxes	6,349	6,246	8,275
Net income (loss)	22,350	21,714	28,027
Preferred stock dividends of subsidiaries	534	534	534
Net income	21,816	21,180	27,493
Preferred stock dividends of Hawaiian Electric	0	0	0
Net income for common stock	21,816	21,180	27,493
Hawaiian Electric Company, Inc. and Subsidiaries | Reportable Legal Entities | Maui Electric
Condensed Income Statements, Captions [Line Items]
Revenues	470,355	365,256	323,430
Expenses
Fuel oil	214,575	121,445	88,985
Purchased power	48,713	52,855	48,957
Other operation and maintenance	85,706	83,013	88,665
Depreciation	35,295	33,661	32,305
Taxes, other than income taxes	43,645	34,251	30,450
Total expenses	427,934	325,225	289,362
Operating income	42,421	40,031	34,068
Allowance for equity funds used during construction	1,212	1,214	890
Equity in earnings of subsidiaries	0	0	0
Retirement defined benefits credit (expense)—other than service costs	(127)	(128)	(141)
Interest expense and other charges, net	(10,824)	(10,439)	(9,651)
Allowance for borrowed funds used during construction	370	436	292
Income before income taxes	33,052	31,114	25,458
Income taxes	6,994	6,560	5,066
Net income (loss)	26,058	24,554	20,392
Preferred stock dividends of subsidiaries	381	381	381
Net income	25,677	24,173	20,011
Preferred stock dividends of Hawaiian Electric	0	0	0
Net income for common stock	25,677	24,173	20,011
Hawaiian Electric Company, Inc. and Subsidiaries | Reportable Legal Entities | Other subsidiaries
Expenses
Allowance for equity funds used during construction	0	0	0
Net income (loss)	0	0	0
Hawaiian Electric Company, Inc. and Subsidiaries | Consolidating adjustments
Condensed Income Statements, Captions [Line Items]
Revenues	(327)	(25)	(636)
Expenses
Fuel oil	0	0	0
Purchased power	0	0	0
Other operation and maintenance	0	0	0
Depreciation	0	0	0
Taxes, other than income taxes	0	0	0
Total expenses	0	0	0
Operating income	(327)	(25)	(636)
Allowance for equity funds used during construction	0	0	0
Equity in earnings of subsidiaries	(47,493)	(45,353)	(47,504)
Retirement defined benefits credit (expense)—other than service costs	0	0	0
Interest expense and other charges, net	327	25	636
Allowance for borrowed funds used during construction	0	0	0
Income before income taxes	(47,493)	(45,353)	(47,504)
Income taxes	0	0	0
Net income (loss)	(47,493)	(45,353)	(47,504)
Preferred stock dividends of subsidiaries	0	0	0
Net income	(47,493)	(45,353)	(47,504)
Preferred stock dividends of Hawaiian Electric	0	0	0
Net income for common stock	$ (47,493)	$ (45,353)	$ (47,504)