Electric utility segment - Power purchase agreements (Details) $ in Thousands		1 Months Ended				3 Months Ended		12 Months Ended
	Apr. 21, 2023 MWh MW	Oct. 31, 2021	Jul. 31, 2018 MW	Feb. 28, 2018 USD ($) agreement MW	May 31, 2012 MW	Mar. 31, 2023 USD ($) project	Mar. 31, 2022 USD ($)	Dec. 31, 1988 MW	Dec. 31, 2022 USD ($)
Regulatory Projects and Legal Obligations [Line Items]
Finance lease liabilities						$ 88,024			$ 48,709
Kalaeloa
Regulatory Projects and Legal Obligations [Line Items]
Purchase commitment, extension period		10 years
Stage 1 Renewable PPAs
Regulatory Projects and Legal Obligations [Line Items]
Number of power purchase agreements (PPAs) (in agreements) | agreement				8
Minimum power volume required (in megawatts) | MW				274.5
Estimated annual cost				$ 64,500
Long term purchase commitments, number of projects | project						2
Finance lease liabilities						$ 88,000
Financing lease right-of-use assets						88,000
Stage 1 Renewable PPAs | Subsequent Event
Regulatory Projects and Legal Obligations [Line Items]
Generates in minimum volume required (in megawatts) | MW	30
Generates in minimum volume required (in megawatts hour) | MWh	120
Hu Honua Bioenergy, LLC
Regulatory Projects and Legal Obligations [Line Items]
Minimum power volume required (in megawatts) | MW					21.5
Molokai New Energy Partners
Regulatory Projects and Legal Obligations [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
Hawaiian Electric, Parent
Regulatory Projects and Legal Obligations [Line Items]
Purchased power						153,000	$ 164,000
Hawaiian Electric, Parent | Kalaeloa
Regulatory Projects and Legal Obligations [Line Items]
Purchased power						67,000	60,000
Increased power purchase commitment capacity (in megawatts) | MW								208
Hawaiian Electric, Parent | AES Hawaii
Regulatory Projects and Legal Obligations [Line Items]
Purchased power						0	27,000
Hawaiian Electric, Parent | HPOWER
Regulatory Projects and Legal Obligations [Line Items]
Purchased power						18,000	19,000
Hawaiian Electric, Parent | Hamakua Energy
Regulatory Projects and Legal Obligations [Line Items]
Purchased power						20,000	16,000
Hawaiian Electric, Parent | Puna Geothermal Venture
Regulatory Projects and Legal Obligations [Line Items]
Purchased power						8,000	10,000
Hawaiian Electric, Parent | Wind IPPs
Regulatory Projects and Legal Obligations [Line Items]
Purchased power						24,000	18,000
Hawaiian Electric, Parent | Solar IPPs
Regulatory Projects and Legal Obligations [Line Items]
Purchased power						14,000	13,000
Hawaiian Electric, Parent | Other IPPs
Regulatory Projects and Legal Obligations [Line Items]
Purchased power						$ 2,000	$ 1,000