Utility Plant and Intangible Assets - Schedule of Components (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2023	Dec. 31, 2022
Intangible assets
Total intangible assets		$ 32,345	$ 31,938
Less — accumulated amortization		(27,275)	(26,811)
Intangible assets, net of amortization		5,070	5,127
Intangible assets not subject to amortization	[1]	383	383
Total utility plant, at cost		$ 2,279,621	$ 2,178,349
Conservation programs
Intangible assets
Weighted Average Amortization Period (in years)		3 years	3 years
Total intangible assets		$ 9,486	$ 9,486
Water and water service rights
Intangible assets
Weighted Average Amortization Period (in years)		30 years	30 years
Total intangible assets	[2]	$ 8,695	$ 8,695
Water planning studies
Intangible assets
Weighted Average Amortization Period (in years)		14 years	14 years
Total intangible assets		$ 14,164	$ 13,757
GSWC
Intangible assets
Total intangible assets		30,536	30,129
Less — accumulated amortization		(26,294)	(25,374)
Intangible assets, net of amortization		4,242	4,755
Intangible assets not subject to amortization	[1]	$ 382	$ 382
GSWC | Conservation programs
Intangible assets
Weighted Average Amortization Period (in years)		3 years	3 years
Total intangible assets		$ 9,486	$ 9,486
GSWC | Water and water service rights
Intangible assets
Weighted Average Amortization Period (in years)		30 years	30 years
Total intangible assets	[2]	$ 8,124	$ 8,124
GSWC | Water planning studies
Intangible assets
Weighted Average Amortization Period (in years)		14 years	14 years
Total intangible assets		$ 12,926	$ 12,519
Intangible assets | American States Utility Services
Intangible assets
Total utility plant, at cost		$ 571	$ 571

[1] The intangible assets not subject to amortization primarily consist of organization and consent fees.

[2] Includes intangible assets of $571,000 for contracted services included in “Other Property and Investments” on the consolidated balance sheets as of December 31, 2023 and 2022.