Consolidated Statements of Capitalization - HECO (Parenthetical) - $ / shares	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023
Common stock, authorized shares (in shares)	200,000,000	200,000,000
Common stock, outstanding shares (in shares)	172,465,608	110,151,798
Hawaiian Electric Company, Inc. and Subsidiaries
Common stock, par value (in dollars per share)	$ 6.667	$ 6.667
Common stock, authorized shares (in shares)	50,000,000	50,000,000
Common stock, outstanding shares (in shares)	17,854,278	17,854,278
Hawaiian Electric Company, Inc. and Subsidiaries | Special Purpose Revenue Bonds | 3.50%, Series 2019, due 2049
Debt instrument, stated interest rate (as percent)	3.50%
Hawaiian Electric Company, Inc. and Subsidiaries | Special Purpose Revenue Bonds | 3.20%, Refunding series 2019, due 2039
Debt instrument, stated interest rate (as percent)	3.20%
Hawaiian Electric Company, Inc. and Subsidiaries | Special Purpose Revenue Bonds | 3.10%, Refunding series 2017A, due 2026
Debt instrument, stated interest rate (as percent)	3.10%
Hawaiian Electric Company, Inc. and Subsidiaries | Special Purpose Revenue Bonds | 4.00%, Refunding series 2017B, due 2037
Debt instrument, stated interest rate (as percent)	4.00%
Hawaiian Electric Company, Inc. and Subsidiaries | Special Purpose Revenue Bonds | 3.25%, Refunding series 2015, due 2025
Debt instrument, stated interest rate (as percent)	3.25%
Hawaiian Electric Company, Inc. and Subsidiaries | Senior notes | 6.11%, Series 2023A, due 2030
Debt instrument, stated interest rate (as percent)	6.11%
Hawaiian Electric Company, Inc. and Subsidiaries | Senior notes | 6.25%, Series 2023A and 2023B, due 2033
Debt instrument, stated interest rate (as percent)	6.25%
Hawaiian Electric Company, Inc. and Subsidiaries | Senior notes | 6.70%, Series 2023C, due 2053
Debt instrument, stated interest rate (as percent)	6.70%
Hawaiian Electric Company, Inc. and Subsidiaries | Senior notes | 3.70%, Series 2022A, due 2032
Debt instrument, stated interest rate (as percent)	3.70%
Hawaiian Electric Company, Inc. and Subsidiaries | Senior notes | 3.51%, Series 2020C and 2020E, due 2050
Debt instrument, stated interest rate (as percent)	3.51%
Hawaiian Electric Company, Inc. and Subsidiaries | Senior notes | 3.28%, Series 2020B and 2020D, due 2040
Debt instrument, stated interest rate (as percent)	3.28%
Hawaiian Electric Company, Inc. and Subsidiaries | Senior notes | 3.96%, Series 2020A, 2020B and 2020C, due 2050
Debt instrument, stated interest rate (as percent)	3.96%
Hawaiian Electric Company, Inc. and Subsidiaries | Senior notes | 3.31%, Series 2020A and 2020B, due 2030
Debt instrument, stated interest rate (as percent)	3.31%
Hawaiian Electric Company, Inc. and Subsidiaries | Senior notes | 4.21%, Series 2019A, due 2034
Debt instrument, stated interest rate (as percent)	4.21%
Hawaiian Electric Company, Inc. and Subsidiaries | Senior notes | 4.38%, Series 2018A, due 2028
Debt instrument, stated interest rate (as percent)	4.38%
Hawaiian Electric Company, Inc. and Subsidiaries | Senior notes | 4.53%, Series 2018B, due 2033
Debt instrument, stated interest rate (as percent)	4.53%
Hawaiian Electric Company, Inc. and Subsidiaries | Senior notes | 4.72%, Series 2018C, due 2048
Debt instrument, stated interest rate (as percent)	4.72%
Hawaiian Electric Company, Inc. and Subsidiaries | Senior notes | 4.31%, Series 2017A, due 2047
Debt instrument, stated interest rate (as percent)	4.31%
Hawaiian Electric Company, Inc. and Subsidiaries | Senior notes | 4.54%, Series 2016A, due 2046
Debt instrument, stated interest rate (as percent)	4.54%
Hawaiian Electric Company, Inc. and Subsidiaries | Senior notes | 5.23%, Series 2015A, due 2045
Debt instrument, stated interest rate (as percent)	5.23%
Hawaiian Electric Company, Inc. and Subsidiaries | Senior notes | 4.84%, Series 2013A, 2013B and 2013C, due 2027
Debt instrument, stated interest rate (as percent)	4.84%
Hawaiian Electric Company, Inc. and Subsidiaries | Senior notes | 5.65%, Series 2013B and 2013C, due 2043
Debt instrument, stated interest rate (as percent)	5.65%
Hawaiian Electric Company, Inc. and Subsidiaries | Senior notes | 4.72%, Series 2012D, due 2029
Debt instrument, stated interest rate (as percent)	4.72%
Hawaiian Electric Company, Inc. and Subsidiaries | Senior notes | 5.39%, Series 2012E, due 2042
Debt instrument, stated interest rate (as percent)	5.39%
Hawaiian Electric Company, Inc. and Subsidiaries | Senior notes | 4.53%, Series 2012F, due 2032
Debt instrument, stated interest rate (as percent)	4.53%
Hawaiian Electric Company, Inc. and Subsidiaries | Line of credit facility | Revolving credit facility SOFR +1.80%, due 2026 and 2027
Debt instrument, stated interest rate (as percent)	1.80%
Hawaiian Electric Company, Inc. and Subsidiaries | Preferred Stock $20 Par Value
Preferred stock, authorized shares (in shares)	5,000,000	5,000,000
Preferred stock, par value (in dollars per share)	$ 20	$ 20
Hawaiian Electric Company, Inc. and Subsidiaries | Preferred Stock $100 Par Value
Preferred stock, authorized shares (in shares)	7,000,000	7,000,000
Preferred stock, par value (in dollars per share)	$ 100	$ 100
Hawaiian Electric | Series C, 4.25% Preferred Stock
Preferred stock, par value (in dollars per share)	$ 20	$ 20
Preferred stock, stated dividend rate (as percent)	4.25%	4.25%
Hawaiian Electric | Series D, 5.00% Preferred Stock
Preferred stock, par value (in dollars per share)	$ 20	$ 20
Preferred stock, stated dividend rate (as percent)	5.00%	5.00%
Hawaiian Electric | Series E, 5.00% Preferred Stock
Preferred stock, par value (in dollars per share)	$ 20	$ 20
Preferred stock, stated dividend rate (as percent)	5.00%	5.00%
Hawaiian Electric | Series H, 5.25% Preferred Stock
Preferred stock, par value (in dollars per share)	$ 20	$ 20
Preferred stock, stated dividend rate (as percent)	5.25%	5.25%
Hawaiian Electric | Series I, 5.00% Preferred Stock
Preferred stock, par value (in dollars per share)	$ 20	$ 20
Preferred stock, stated dividend rate (as percent)	5.00%	5.00%
Hawaiian Electric | Series J, 4.75% Preferred Stock
Preferred stock, par value (in dollars per share)	$ 20	$ 20
Preferred stock, stated dividend rate (as percent)	4.75%	4.75%
Hawaiian Electric | Series K, 4.65% Preferred Stock
Preferred stock, par value (in dollars per share)	$ 20	$ 20
Preferred stock, stated dividend rate (as percent)	4.65%	4.65%
Hawaii Electric Light | Series G, 7.625% Preferred Stock
Preferred stock, par value (in dollars per share)	$ 100	$ 100
Preferred stock, stated dividend rate (as percent)	7.625%	7.625%
Maui Electric | Series H, 7.625% Preferred Stock
Preferred stock, par value (in dollars per share)	$ 100	$ 100
Preferred stock, stated dividend rate (as percent)	7.625%	7.625%