Electric utility segment - Unconsolidated Variable Interest Entities (Details)	9 Months Ended
Sep. 30, 2024 agreement entity
Power purchase agreement
Number of IPPs (in entities) \| entity	2
Hawaiian Electric Company
Power purchase agreement
Number of power purchase agreements (PPAs) (in agreements) \| agreement	4

Represents the number of firm power purchase agreements entered into, by the company.

No definition available.

Name:	he_NumberOfPowerPurchaseAgreements
Namespace Prefix:	he_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration