Electric utility segment - Condensed consolidating statement of cash flows (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022
Cash flows from operating activities
Net cash provided by operating activities	$ 180,952	$ 92,585
Cash flows from investing activities
Capital expenditures	(124,297)	(79,163)
Other	2,148	5,340
Net cash used in investing activities	(137,468)	(227,714)
Cash flows from financing activities
Common stock dividends	(39,446)	(38,301)
Proceeds from issuance of long-term debt	150,000	7,312
Net increase (decrease) in short-term borrowings with original maturities of three months or less	(88,666)	17,493
Other	(5,535)	(4,377)
Net cash provided by financing activities	71,139	131,283
Net increase (decrease) in cash, cash equivalents and restricted cash	114,623	(3,846)
Cash, cash equivalents and restricted cash, beginning of period	204,927	311,462
Cash, cash equivalents and restricted cash, end of period	319,550	307,616
Less: Restricted cash	(4,216)	(5,912)	$ (5,050)
Cash and cash equivalents	315,334	301,704	199,877
Hawaiian Electric Consolidated
Cash flows from operating activities
Net cash provided by operating activities	169,355	76,775
Cash flows from investing activities
Capital expenditures	(122,139)	(76,358)
Advances to affiliates	0	0
Other	1,545	1,494
Net cash used in investing activities	(120,594)	(74,864)
Cash flows from financing activities
Common stock dividends	(32,250)	(31,475)
Preferred stock dividends of Hawaiian Electric and subsidiaries	(499)	(499)
Proceeds from issuance of long-term debt	150,000	0
Net increase (decrease) in short-term borrowings with original maturities of three months or less	(87,967)	6,000
Payments of obligations under finance leases	(575)	0
Other	(690)	0
Net cash provided by financing activities	28,019	(25,974)
Net increase (decrease) in cash, cash equivalents and restricted cash	76,780	(24,063)
Cash, cash equivalents and restricted cash, beginning of period	39,242	55,258
Cash, cash equivalents and restricted cash, end of period	116,022	31,195
Less: Restricted cash	0	(2,140)
Cash and cash equivalents	116,022	29,055	39,242
Hawaiian Electric Consolidated | Reportable Legal Entities | Hawaiian Electric (parent only)
Cash flows from operating activities
Net cash provided by operating activities	143,356	55,669
Cash flows from investing activities
Capital expenditures	(74,916)	(44,084)
Advances to affiliates	0	(4,000)
Other	1,094	961
Net cash used in investing activities	(73,822)	(47,123)
Cash flows from financing activities
Common stock dividends	(32,250)	(31,475)
Preferred stock dividends of Hawaiian Electric and subsidiaries	(270)	(270)
Proceeds from issuance of long-term debt	100,000
Net increase (decrease) in short-term borrowings with original maturities of three months or less	(114,167)	18,800
Payments of obligations under finance leases	(575)
Other	(458)
Net cash provided by financing activities	(47,720)	(12,945)
Net increase (decrease) in cash, cash equivalents and restricted cash	21,814	(4,399)
Cash, cash equivalents and restricted cash, beginning of period	27,579	26,433
Cash, cash equivalents and restricted cash, end of period	49,393	22,034
Less: Restricted cash		(2,140)
Cash and cash equivalents	49,393	19,894	27,579
Hawaiian Electric Consolidated | Reportable Legal Entities | Hawaii Electric Light
Cash flows from operating activities
Net cash provided by operating activities	18,733	15,778
Cash flows from investing activities
Capital expenditures	(20,747)	(15,133)
Advances to affiliates	4,500	0
Other	153	280
Net cash used in investing activities	(16,094)	(14,853)
Cash flows from financing activities
Common stock dividends	(4,475)	(4,100)
Preferred stock dividends of Hawaiian Electric and subsidiaries	(134)	(134)
Proceeds from issuance of long-term debt	25,000
Net increase (decrease) in short-term borrowings with original maturities of three months or less	0	4,000
Payments of obligations under finance leases	0
Other	(116)
Net cash provided by financing activities	20,275	(234)
Net increase (decrease) in cash, cash equivalents and restricted cash	22,914	691
Cash, cash equivalents and restricted cash, beginning of period	5,092	5,326
Cash, cash equivalents and restricted cash, end of period	28,006	6,017
Less: Restricted cash		0
Cash and cash equivalents	28,006	6,017	5,092
Hawaiian Electric Consolidated | Reportable Legal Entities | Maui Electric
Cash flows from operating activities
Net cash provided by operating activities	15,416	13,228
Cash flows from investing activities
Capital expenditures	(26,476)	(17,141)
Advances to affiliates	21,700	(12,800)
Other	298	253
Net cash used in investing activities	(4,478)	(29,688)
Cash flows from financing activities
Common stock dividends	(3,675)	(3,800)
Preferred stock dividends of Hawaiian Electric and subsidiaries	(95)	(95)
Proceeds from issuance of long-term debt	25,000
Net increase (decrease) in short-term borrowings with original maturities of three months or less	0	0
Payments of obligations under finance leases	0
Other	(116)
Net cash provided by financing activities	21,114	(3,895)
Net increase (decrease) in cash, cash equivalents and restricted cash	32,052	(20,355)
Cash, cash equivalents and restricted cash, beginning of period	6,494	23,422
Cash, cash equivalents and restricted cash, end of period	38,546	3,067
Less: Restricted cash		0
Cash and cash equivalents	38,546	3,067	6,494
Hawaiian Electric Consolidated | Reportable Legal Entities | Other subsidiaries
Cash flows from operating activities
Net cash provided by operating activities	0	0
Cash flows from investing activities
Capital expenditures	0	0
Advances to affiliates	0	0
Other	0	0
Net cash used in investing activities	0	0
Cash flows from financing activities
Common stock dividends	0	0
Preferred stock dividends of Hawaiian Electric and subsidiaries	0	0
Proceeds from issuance of long-term debt	0
Net increase (decrease) in short-term borrowings with original maturities of three months or less	0	0
Payments of obligations under finance leases	0
Other	0
Net cash provided by financing activities	0	0
Net increase (decrease) in cash, cash equivalents and restricted cash	0	0
Cash, cash equivalents and restricted cash, beginning of period	77	77
Cash, cash equivalents and restricted cash, end of period	77	77
Less: Restricted cash		0
Cash and cash equivalents	77	77	77
Hawaiian Electric Consolidated | Consolidating adjustments
Cash flows from operating activities
Net cash provided by operating activities	(8,150)	(7,900)
Cash flows from investing activities
Capital expenditures	0	0
Advances to affiliates	(26,200)	16,800
Other	0	0
Net cash used in investing activities	(26,200)	16,800
Cash flows from financing activities
Common stock dividends	8,150	7,900
Preferred stock dividends of Hawaiian Electric and subsidiaries	0	0
Proceeds from issuance of long-term debt	0
Net increase (decrease) in short-term borrowings with original maturities of three months or less	26,200	(16,800)
Payments of obligations under finance leases	0
Other	0
Net cash provided by financing activities	34,350	(8,900)
Net increase (decrease) in cash, cash equivalents and restricted cash	0	0
Cash, cash equivalents and restricted cash, beginning of period	0	0
Cash, cash equivalents and restricted cash, end of period	0	0
Less: Restricted cash		0
Cash and cash equivalents	$ 0	$ 0	$ 0