Summary of Significant Accounting Policies - Narrative (Details) - USD ($) $ in Millions	3 Months Ended	4 Months Ended	15 Months Ended
	Mar. 31, 2024	Apr. 30, 2024	Mar. 31, 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
Subsequent Event
Disaggregation of Revenue [Line Items]
Application amount for eligible customer arrearages		$ 82.0
IRMA long-term regulatory liability
Disaggregation of Revenue [Line Items]
Regulated revenue			$ 80.7
MWRAM
Disaggregation of Revenue [Line Items]
Regulated revenue			$ 31.1