Summary of Significant Accounting Policies - Narrative (Details) - USD ($)	3 Months Ended			9 Months Ended
	Sep. 30, 2024	Jun. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023	Apr. 30, 2024
Disaggregation of Revenue [Line Items]
Maximum collection period in which deferred net WRAM and MCBA revenues and associated costs will be recognized				24 months
Funds received from government program						$ 82,000,000
Decrease to past due customer balances		$ 57,500,000
IRMA Long-term Regulatory Liability
Disaggregation of Revenue [Line Items]
Regulated revenue	$ 0		$ 0	$ 88,600,000	$ 0
MWRAM
Disaggregation of Revenue [Line Items]
Regulated revenue	$ 9,400,000			$ 29,800,000