Electric utility segment - Commitments and contingencies (Details) $ in Thousands		1 Months Ended				3 Months Ended	12 Months Ended
	Mar. 28, 2024 USD ($) MW	Apr. 30, 2024 USD ($)	Feb. 28, 2023	Jul. 31, 2018 MW	May 31, 2012 MW	Mar. 31, 2024 USD ($) agreement MW	Dec. 31, 2022 USD ($)	Dec. 31, 2019 agreement	Dec. 31, 2023 USD ($)
Long-term Purchase Commitment [Line Items]
Operating lease right-of-use assets						$ 91,182			$ 94,905
Environmental loss contingency, statement of financial position, not disclosed						reserve account balance
Purchase obligation									1,700,000
Maui Electric
Long-term Purchase Commitment [Line Items]
Additional accrued investigation and estimated cleanup costs						$ 2,500
Hawaiian Electric, Parent | PCB Contamination
Long-term Purchase Commitment [Line Items]
Valuation allowances and reserves						9,600
Hawaiian Electric Company, Inc. and Subsidiaries
Long-term Purchase Commitment [Line Items]
Operating lease right-of-use assets						68,217			$ 71,877
Notice period, pre-cursor to citizen's suit			60 days
Number of power purchase agreements (PPAs) (in agreements) | agreement								7
Hu Honua Bioenergy, LLC
Long-term Purchase Commitment [Line Items]
Minimum power volume required (in megawatts) | MW					21.5
Molokai New Energy Partners
Long-term Purchase Commitment [Line Items]
Total contracted PV capacity (in megawatts) | MW				4.88
Total contracted battery energy storage system capacity | MW				3
Maximum power volume to be delivered (in megawatts) | MW				2.64
James Campbell Company | Hawaiian Electric, Parent | Kapolei Petroleum Contamination
Long-term Purchase Commitment [Line Items]
Environmental remediation expense							$ 800
James Campbell Company | Hawaiian Electric, Parent | Kapolei Petroleum Contamination | Subsequent Event
Long-term Purchase Commitment [Line Items]
Environmental remediation expense		$ 1,400
AES Hawaii | Hawaiian Electric Company, Inc. and Subsidiaries
Long-term Purchase Commitment [Line Items]
Minimum power volume required (in megawatts) | MW	12.5
Total contracted PV capacity (in megawatts) | MW	50
Annual payment	$ 3,200
Operating lease right-of-use assets						$ 12,200
Stage 1 And 2 Renewable PPAs | Hawaiian Electric Company, Inc. and Subsidiaries
Long-term Purchase Commitment [Line Items]
Minimum power volume required (in megawatts) | MW						117.5
Total contracted PV capacity (in megawatts) | MW						1,035
Number of power purchase agreements (PPAs) (in agreements) | agreement						5