Summary of Significant Accounting Policies - Nonutility Properties and Real Estate Investments (Details) - USD ($) $ in Thousands	Dec. 31, 2025	Dec. 31, 2024
Components of Real Estate Investments [Abstract]
Land	$ 914	$ 915
Wholesale water supply assets	0	0
Buildings and improvements	769	399
Subtotal	1,683	1,314
Less: accumulated depreciation and amortization	103	98
Net nonutility properties	$ 1,580	$ 1,216
Building and Building Improvements \| Minimum
Components of Real Estate Investments [Abstract]
Estimated useful life	7 years
Building and Building Improvements \| Maximum
Components of Real Estate Investments [Abstract]
Estimated useful life	39 years

Wholesale Water Supply Assets

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Amount of accumulated depreciation, depletion and amortization for physical assets used in the normal conduct of business to produce goods and services.

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Aggregate of the carrying amounts as of the balance sheet date of investments in building and building improvements.

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Amount before accumulated depletion of real estate held for productive use, excluding land held for sale.

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Amount before accumulated depreciation, depletion and amortization of physical assets used in the normal conduct of business and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures.

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Amount after accumulated depreciation, depletion and amortization of physical assets used in the normal conduct of business to produce goods and services and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures.

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Useful life on which depreciation was computed for entities with a substantial portion of business acquiring and holding investment real estate, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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