Employee Benefit Plans - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Defined Benefit Plan Disclosure [Line Items]
Increase (Decrease) in Regulatory Assets and Liabilities	$ 2,234	$ 35,863
GSWC
Defined Benefit Plan Disclosure [Line Items]
Increase (Decrease) in Regulatory Assets and Liabilities	3,935	34,059
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Contributions by Employer	3,300
Increase (Decrease) in Regulatory Assets and Liabilities	0	92
Pension Benefits | GSWC
Defined Benefit Plan Disclosure [Line Items]
Regulatory adjustment — deferred	(1,231)
Pension Benefits | BVES
Defined Benefit Plan Disclosure [Line Items]
Regulatory adjustment — deferred	(368)
Pension Benefits | Water: | GSWC
Defined Benefit Plan Disclosure [Line Items]
Increase (Decrease) in Regulatory Assets and Liabilities	$ 134	$ (92)