Revenues - Narrative (Details) $ in Millions	3 Months Ended	6 Months Ended
	Jun. 30, 2026 USD ($) contract	Jun. 30, 2026 USD ($) contract
ASUS
Disaggregation of Revenue [Line Items]
Revenue recognized	$ 4.6	$ 8.2
Revenue, remaining performance obligation, amount	$ 4,200.0	$ 4,200.0
ASUS | Minimum
Disaggregation of Revenue [Line Items]
Revenue, remaining performance obligation, expected timing of satisfaction, period	13 years	13 years
ASUS | Maximum
Disaggregation of Revenue [Line Items]
Period of fixed price contracts to operate and maintain water systems at various military bases		50 years
Revenue, remaining performance obligation, expected timing of satisfaction, period	48 years	48 years
Bay State Utility Service LLC (" BSUS")
Disaggregation of Revenue [Line Items]
Number of contracts with 15 year contract | contract	1	1
Golden State Water Company and Bear Valley Electric Service Inc. | Revenue Benchmark | Customer Concentration Risk
Disaggregation of Revenue [Line Items]
Concentration risk, percentage		90.00%
Contracted services: | Bay State Utility Service LLC (" BSUS")
Disaggregation of Revenue [Line Items]
Period of fixed price contracts to operate and maintain water systems at various military bases		15 years