Employee Benefit Plans - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Defined Benefit Plan Disclosure [Line Items]
Increase (Decrease) in Regulatory Assets and Liabilities			$ 86,070	$ 14,065
GSWC
Defined Benefit Plan Disclosure [Line Items]
Increase (Decrease) in Regulatory Assets and Liabilities			81,854	12,549
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Contributions by Employer			2,900
Increase (Decrease) in Regulatory Assets and Liabilities	$ 27	$ 0	211	0
Pension Benefits | GSWC
Defined Benefit Plan Disclosure [Line Items]
Regulatory adjustment — deferred	(1,138)		(1,138)
Pension Benefits | BVES
Defined Benefit Plan Disclosure [Line Items]
Regulatory adjustment — deferred	$ (205)		$ (205)
Pension Benefits | Water: | GSWC
Defined Benefit Plan Disclosure [Line Items]
Increase (Decrease) in Regulatory Assets and Liabilities		$ 27		$ 211