Summary of Significant Accounting Policies - Narrative (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
	Jun. 30, 2024	Jun. 30, 2024	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			$ 82.0
Decrease to past due customer balances	$ 57.5
IRMA long-term regulatory liability
Disaggregation of Revenue [Line Items]
Regulated revenue	7.9	$ 88.6
MWRAM
Disaggregation of Revenue [Line Items]
Regulated revenue	$ 8.2	$ 39.3