Business Segments - Narrative (Details) $ in Thousands	3 Months Ended			6 Months Ended
	Jun. 30, 2023 USD ($)	Mar. 31, 2023 USD ($)	Jun. 30, 2022 USD ($)	Jun. 30, 2023 USD ($) item segment	Jun. 30, 2022 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 | $	$ 155	$ 212	$ 95	$ 523	$ 189
Parent Company
Details of reportable segment
Number of reportable segments | segment				3