Share-based compensation - Schedule of Fair Value Assumptions (Details) - LTIP linked to TRS - $ / shares |
6 Months Ended | |
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Jun. 30, 2026 |
Jun. 30, 2025 |
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| Fair Value Measurement Inputs and Valuation Techniques [Line Items] | ||
| Risk-free interest rate | 3.49% | 4.37% |
| Expected life in years | 3 years | 3 years |
| Expected volatility | 65.30% | 64.70% |
| Range of expected volatility for Peer Group, minimum rate | 16.80% | 15.30% |
| Range of expected volatility for Peer Group, maximum rate | 65.30% | 64.70% |
| Grant-date fair value (in dollars per share) | $ 17.04 | $ 11.39 |
| Hawaiian Electric Company, Inc. and Subsidiaries | ||
| Fair Value Measurement Inputs and Valuation Techniques [Line Items] | ||
| Grant-date fair value (in dollars per share) | $ 17.04 | $ 11.12 |
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- Definition Represents the estimated fair value at grant date for nonvested equity-based awards on other than stock (or unit) option plans. No definition available.
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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. Reference 1: http://www.xbrl.org/2003/role/exampleRef
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- Definition The estimated measure of the percentage by which a share price is expected to fluctuate during a period. Volatility also may be defined as a probability-weighted measure of the dispersion of returns about the mean. The volatility of a share price is the standard deviation of the continuously compounded rates of return on the share over a specified period. That is the same as the standard deviation of the differences in the natural logarithms of the stock prices plus dividends, if any, over the period. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition The estimated measure of the maximum percentage by which a share price is expected to fluctuate during a period. Volatility also may be defined as a probability-weighted measure of the dispersion of returns about the mean. The volatility of a share price is the standard deviation of the continuously compounded rates of return on the share over a specified period. That is the same as the standard deviation of the differences in the natural logarithms of the stock prices plus dividends, if any, over the period. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition The estimated measure of the minimum percentage by which a share price is expected to fluctuate during a period. Volatility also may be defined as a probability-weighted measure of the dispersion of returns about the mean. The volatility of a share price is the standard deviation of the continuously compounded rates of return on the share over a specified period. That is the same as the standard deviation of the differences in the natural logarithms of the stock prices plus dividends, if any, over the period. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition The risk-free interest rate assumption that is used in valuing an option on its own shares. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Expected term of award under share-based payment arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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