Stock-Based Compensation Plans - Narrative Restricted Stock (Details) $ in Thousands	12 Months Ended
Dec. 31, 2025 USD ($)
Stock compensation plans
Vesting period	3 years
Unrecognized compensation cost	$ 300
Performance awards
Stock compensation plans
Period to meet the performance goals	3 years
Vesting period	3 years
Restricted Stock Units
Stock compensation plans
Unrecognized compensation cost related to performance awards	$ 700
2000 and 2008 Employee Plans \| Performance awards
Stock compensation plans
Percentage of rights vesting in the first two years from the date of grant	33.00%
Percentage of rights vesting in the third year from the date of grant	34.00%
Vesting period	3 years
2000 and 2008 Employee Plans \| Restricted Stock Units
Stock compensation plans
Percentage of rights vesting in the first two years from the date of grant	33.00%
Percentage of rights vesting in the third year from the date of grant	34.00%
2000 and 2008 Employee Plans \| Nonqualified stock options
Stock compensation plans
Percentage of rights vesting in the third year from the date of grant	34.00%
Weighted Average
Stock compensation plans
Expected recognition period for unrecognized compensation cost	1 year 6 months
Weighted Average \| Restricted Stock
Stock compensation plans
Expected recognition period for unrecognized compensation cost	1 year 6 months 3 days
Minimum
Stock compensation plans
Percentage of target amount of performance shares	0.00%
Maximum
Stock compensation plans
Percentage of target amount of performance shares	200.00%
Maximum \| American States Utility Services
Stock compensation plans
Percentage of target amount of performance shares	250.00%

Percentage of Target Amount of Performance Shares

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Period in which 33% vesting rights is earned by awarded of the grant, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Description of award terms as to how many shares or portion of an award are no longer contingent on satisfaction of either a service condition, market condition or a performance condition, in the third year from the date of grant, thereby giving the employee the legal right to convert the award to shares, expressed as a percentage.

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Amount of cost not yet recognized for nonvested award under share-based payment arrangement.

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Weighted-average period over which cost not yet recognized is expected to be recognized for award under share-based payment arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

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Amount of cost to be recognized for nonvested award under share-based payment arrangement. Excludes share and unit options.

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Estimated period over which an employee is required to provide service in exchange for the equity-based payment award, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Period over which grantee's right to exercise award under share-based payment arrangement is no longer contingent on satisfaction of service or performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Includes, but is not limited to, combination of market, performance or service condition.

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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.

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