Maui windstorm and wildfires - Utilities Charged (Details) - Natural Disasters and Other Casualty Events - Hawaiian Electric Company, Inc. and Subsidiaries $ in Millions	Sep. 30, 2023 USD ($)
Public Utilities, General Disclosures [Line Items]
One 'Ohana Initiative contribution	$ 75
Insurance recovery	$ (75)

Carrying amount as of the balance sheet date of amounts expected to be recovered under the terms of insurance contracts.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(17))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480566/210-10-S99-1

Name:	us-gaap_EstimatedInsuranceRecoveries
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant