Earnings Per Share / Capital Stock- Narrative (Details) - USD ($)	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022	Feb. 27, 2024
Additional disclosure
Exercise of stock options and other issuance of Common Shares	25,196	18,371	25,956
Proceeds from Stock Options Exercised, Distributed to Subsidiaries	$ 0	$ 0	$ 0
Dividend Reinvestment Plan Common Stock Capital Shares Reserved for Future Issuance	1,055,948
Common Shares authorized for issuance but unissued under 401(k) Plan	387,300
Issuance of Common Shares from an at-the-market program, net of issuance costs	$ 88,661,000
Sale of Stock, Maximum Consideration On Transaction				$ 200,000,000
Payments of Stock Issuance Costs	800,000
Payments for Commissions	$ 1,400,000
Weighted Average Number of Shares Outstanding (in shares)	37,464,000	36,976,000	36,955,000
Sale of Stock, Agreement Term	3 years
Sale of Stock, Number of Shares Issued in Transaction	1,145,219
Sale of Stock, Consideration Received on Transaction	$ 89,500,000
Sale of Stock, remaining available for sale	$ 109,100,000
AWR
Additional disclosure
Weighted Average Number of Shares Outstanding (in shares)	37,464,000	36,976,000	36,955,000
GSWC
Additional disclosure
Exercise of stock options and other issuance of Common Shares	2.7586	1	0
Issuance of Common Shares from an at-the-market program, net of issuance costs	$ 40,000,000.0	$ 10,000,000