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Electric utility segment - Regulatory Assets for COVID-19 Related Costs (Details) - Hawaiian Electric Company, Inc. and Subsidiaries - USD ($) $ in Millions |  | 1 Months Ended | 9 Months Ended
--- | --- | --- | ---
Jun. 09, 2022 | Jun. 30, 2022 | Dec. 31, 2021 | Sep. 30, 2023
Regulatory Projects and Legal Obligations [Line Items] |  |  |  |
Recovery of deferral costs | $ 27.8 | $ 27.8 |  |
Recovery of deferral costs period (in years) | 3 years | 3 years |  |
COVID-19 |  |  |  |
Regulatory Projects and Legal Obligations [Line Items] |  |  |  |
Customer bill forgiveness |  |  | $ 2.0 |
Public utilities in regulatory assets |  |  |  | $ 8.8

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- Details
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- Details
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