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Income taxes (Details) | 9 Months Ended
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Sep. 30, 2021 | Sep. 30, 2020
Income Tax Contingency [Line Items] |  |
Effective income tax, percent | 20.00% | 17.00%
Hawaiian Electric Company, Inc. and Subsidiaries |  |
Income Tax Contingency [Line Items] |  |
Effective income tax, percent | 19.00% | 19.00%

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- Definition Percentage of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 12 -URI http://asc.fasb.org/extlink&oid=121826272&loc=d3e32687-109319 + Details
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- Details
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