Fair Value of Financial Instruments - Schedule of Outstanding Long-Term Debt (Details) - USD ($) $ in Thousands	Sep. 30, 2025	Dec. 31, 2024
Fair value of financial instruments
Unamortized debt issuance expense	$ 3,600	$ 3,100
Carrying Amount
Fair value of financial instruments
Long-term debt, fair value	794,310	643,893
Fair Value
Fair value of financial instruments
Long-term debt, fair value	789,513	608,184
GOLDEN STATE WATER COMPANY
Fair value of financial instruments
Unamortized debt issuance expense	3,200	3,000
GOLDEN STATE WATER COMPANY \| Carrying Amount
Fair value of financial instruments
Long-term debt, fair value	709,310	608,893
GOLDEN STATE WATER COMPANY \| Fair Value
Fair value of financial instruments
Long-term debt, fair value	$ 702,043	$ 575,749

The fair value amount of long-term debt whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission.

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+ Details