Regulatory Matters - Schedule of Regulatory Assets (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Schedule of Regulatory Assets and Liabilities [Line Items]
Net Regulatory assets	$ 17,626	$ (25,454)
GSWC
Schedule of Regulatory Assets and Liabilities [Line Items]
Net Regulatory assets	9,249	(26,574)
GSWC | Other regulatory liabilities
Schedule of Regulatory Assets and Liabilities [Line Items]
Net Regulatory assets	(13,198)	(8,815)
BVES | Other regulatory liabilities
Schedule of Regulatory Assets and Liabilities [Line Items]
Net Regulatory assets	(8,565)	(8,005)
2022/2023 general rate case memorandum accounts (unbilled revenue) | GSWC
Schedule of Regulatory Assets and Liabilities [Line Items]
Net Regulatory assets	38,419	0
Water revenue adjustment mechanism, net of the modified cost balancing account | GSWC
Schedule of Regulatory Assets and Liabilities [Line Items]
Net Regulatory assets	29,069	31,803
COVID-19 memorandum account | GSWC
Schedule of Regulatory Assets and Liabilities [Line Items]
Net Regulatory assets	3,540	3,478
Excess deferred income taxes | GSWC
Schedule of Regulatory Assets and Liabilities [Line Items]
Net Regulatory assets	(71,418)	(71,870)
Flowed-through income taxes | GSWC
Schedule of Regulatory Assets and Liabilities [Line Items]
Net Regulatory assets	447	(1,134)
Other regulatory assets | GSWC
Schedule of Regulatory Assets and Liabilities [Line Items]
Net Regulatory assets	22,390	19,964
Other regulatory assets | BVES
Schedule of Regulatory Assets and Liabilities [Line Items]
Net Regulatory assets	9,480	7,965
Derivative instrument memorandum account (Note 5) | BVES
Schedule of Regulatory Assets and Liabilities [Line Items]
Net Regulatory assets	(6,669)	(11,847)
Wildfire mitigation and other fire prevention related costs memorandum accounts | BVES
Schedule of Regulatory Assets and Liabilities [Line Items]
Net Regulatory assets	$ 14,131	$ 13,007