Long-Term Debt (Details) $ in Millions	Dec. 31, 2025 USD ($)	May 29, 2025 USD ($)	Mar. 13, 2025 USD ($)	Feb. 12, 2025 USD ($)	Jun. 05, 2024 USD ($)	Jan. 13, 2023 USD ($)
Debt Instrument [Line Items]
Ratio of Indebtedness to EBITDA	8
GSWC
Debt Instrument [Line Items]
Ratio of indebtedness to net capital	0.4352
Ratio of Indebtedness to EBITDA	3.4
GSWC | Financing Applications
Debt Instrument [Line Items]
Regulatory Rate Case Filings Requested Authorization For Debt And Equity Issuance Amount			$ 750.0
GSWC | Maximum
Debt Instrument [Line Items]
Ratio of indebtedness to net capital	0.6667
Unsecured Private Placement Notes | GSWC
Debt Instrument [Line Items]
Debt instrument, face amount	$ 100.0	$ 100.0			$ 65.0	$ 130.0
Interest rate (as a percent)					5.50%
Unsecured Private Placement Notes | BVES
Debt Instrument [Line Items]
Debt instrument, face amount	$ 50.0
Series A Senior Notes at a coupon rate of 5.30% due May 29, 2032 | GSWC
Debt Instrument [Line Items]
Debt instrument, face amount		$ 75.0
Interest rate (as a percent)		5.30%
Series B Senior Notes at a coupon rate of 5.65% due May 29, 2037 | GSWC
Debt Instrument [Line Items]
Debt instrument, face amount		$ 25.0
Interest rate (as a percent)		5.65%
Debt due Feb 2030 | BVES
Debt Instrument [Line Items]
Debt instrument, face amount				$ 50.0
Interest rate (as a percent)				6.12%