Business Segments - Narrative (Details) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2024 USD ($)	Jun. 30, 2023 USD ($)	Jun. 30, 2024 USD ($) item segment	Jun. 30, 2023 USD ($)
GSWC
Details of reportable segment
Number of reportable segments | item			1
Golden State Water Company and Bear Valley Electric Service Inc.
Details of reportable segment
Public Utilities Property Plant and Equipment Depreciation on Transportation Equipment | $	$ 0.2	$ 0.2	$ 0.3	$ 0.5
Parent Company
Details of reportable segment
Number of reportable segments | segment			3