Leases - Amounts Related to Lease Cost and Cash Flows (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Operating Lease Cost [Abstract]
Operating lease cost	$ 17,899	$ 20,924
Variable lease cost	227,567	208,369
Sublease income	(3,280)	(3,031)
Total operating lease cost	242,186	226,262
Finance lease costs:
Amortization of right-of-use assets	20,072	5,981
Interest on lease liabilities	32,377	6,382
Total finance lease cost	52,449	12,363
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows from operating leases	19,475	22,631
Operating cash flows from finance leases	30,972	6,382
Financing cash flows from finance leases	$ 4,678	$ 3,519
Weighted-average remaining lease term (in years):
Operating leases	7 years 2 months 12 days	7 years 6 months
Finance leases	19 years 10 months 24 days	20 years
Weighted-average discount rate:
Operating leases	4.11%	3.11%
Finance leases	8.49%	8.18%
Other leases
Operating Lease Cost [Abstract]
Operating lease cost	$ 13,736	$ 16,853
Variable lease cost	5,378	5,813
Sublease income	(3,280)	(3,031)
Total operating lease cost	15,834	19,635
Finance lease costs:
Amortization of right-of-use assets	574	390
Interest on lease liabilities	33	32
Total finance lease cost	607	422
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows from operating leases	15,604	18,560
Operating cash flows from finance leases	33	32
Financing cash flows from finance leases	$ 559	$ 391
Weighted-average remaining lease term (in years):
Operating leases	8 years 2 months 12 days	8 years 3 months 18 days
Finance leases	3 years 8 months 12 days	1 year 6 months
Weighted-average discount rate:
Operating leases	3.08%	3.03%
Finance leases	2.23%	3.77%
PPAs classified as leases
Operating Lease Cost [Abstract]
Operating lease cost	$ 4,163	$ 4,071
Variable lease cost	222,189	202,556
Sublease income	0	0
Total operating lease cost	226,352	206,627
Finance lease costs:
Amortization of right-of-use assets	19,498	5,591
Interest on lease liabilities	32,344	6,350
Total finance lease cost	51,842	11,941
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows from operating leases	3,871	4,071
Operating cash flows from finance leases	30,939	6,350
Financing cash flows from finance leases	$ 4,119	$ 3,128
Weighted-average remaining lease term (in years):
Operating leases	3 years	4 years
Finance leases	19 years 10 months 24 days	20 years 1 month 6 days
Weighted-average discount rate:
Operating leases	8.78%	3.50%
Finance leases	8.50%	8.18%
Hawaiian Electric Company, Inc. and Subsidiaries
Operating Lease Cost [Abstract]
Operating lease cost	$ 16,984	$ 20,018
Variable lease cost	227,380	208,161
Sublease income	(3,280)	(3,031)
Total operating lease cost	241,084	225,148
Finance lease costs:
Amortization of right-of-use assets	19,498	5,591
Interest on lease liabilities	32,344	6,350
Total finance lease cost	51,842	11,941
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows from operating leases	18,610	21,800
Operating cash flows from finance leases	30,939	6,350
Financing cash flows from finance leases	$ 4,119	$ 3,128	$ 670
Weighted-average remaining lease term (in years):
Operating leases	5 years 7 months 6 days	6 years 3 months 18 days
Finance leases	19 years 10 months 24 days	20 years 1 month 6 days
Weighted-average discount rate:
Operating leases	4.21%	3.03%
Finance leases	8.50%	8.18%
Hawaiian Electric Company, Inc. and Subsidiaries | Other leases
Operating Lease Cost [Abstract]
Operating lease cost	$ 12,821	$ 15,947
Variable lease cost	5,191	5,605
Sublease income	(3,280)	(3,031)
Total operating lease cost	14,732	18,521
Finance lease costs:
Amortization of right-of-use assets	0	0
Interest on lease liabilities	0	0
Total finance lease cost	0	0
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows from operating leases	14,739	17,729
Operating cash flows from finance leases	0	0
Financing cash flows from finance leases	$ 0	$ 0
Weighted-average remaining lease term (in years):
Operating leases	6 years 4 months 24 days	6 years 9 months 18 days
Finance leases	0 years	0 years
Weighted-average discount rate:
Operating leases	2.95%	2.92%
Finance leases	0.00%	0.00%
Hawaiian Electric Company, Inc. and Subsidiaries | PPAs classified as leases
Operating Lease Cost [Abstract]
Operating lease cost	$ 4,163	$ 4,071
Variable lease cost	222,189	202,556
Sublease income	0	0
Total operating lease cost	226,352	206,627
Finance lease costs:
Amortization of right-of-use assets	19,498	5,591
Interest on lease liabilities	32,344	6,350
Total finance lease cost	51,842	11,941
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows from operating leases	3,871	4,071
Operating cash flows from finance leases	30,939	6,350
Financing cash flows from finance leases	$ 4,119	$ 3,128
Weighted-average remaining lease term (in years):
Operating leases	3 years	4 years
Finance leases	19 years 10 months 24 days	20 years 1 month 6 days
Weighted-average discount rate:
Operating leases	8.78%	3.50%
Finance leases	8.50%	8.18%