CONSOLIDATED STATEMENTS OF CHANGES IN COMMON SHAREHOLDERS' EQUITY - USD ($) $ in Thousands	Total	GSWC	Common Stock	Common Stock GSWC	Earnings Reinvested in the Business	Earnings Reinvested in the Business GSWC
Beginning Balance (in shares) at Dec. 31, 2020			36,889,000	170
Beginning Balance at Dec. 31, 2020	$ 641,673	$ 583,298	$ 256,666	$ 354,906	$ 385,007	$ 228,392
Add:
Net Income	$ 94,347	$ 69,215			94,347	69,215
Exercise of stock options and other issuance of Common Shares	47,182	0	47,000
Exercise of stock options and other issuance of Common Shares	$ 0		$ 0
Stock-based compensation, net of taxes paid from shares withheld from employees related to net share settlements	1,616	$ 1,473	1,616	1,473
Dividend equivalent rights on stock-based awards not paid in cash	160	151	$ 160	$ 151
Deduct:
Dividends on Common Shares	51,689	38,300			51,689	38,300
Dividend equivalent rights on stock-based awards	160	151			160	151
Ending Balance (in shares) at Dec. 31, 2021			36,936,000	170
Ending Balance at Dec. 31, 2021	685,947	615,686	$ 258,442	$ 356,530	427,505	259,156
Add:
Net Income	$ 78,396	$ 53,770			78,396	53,770
Exercise of stock options and other issuance of Common Shares	25,956	0	26,000
Exercise of stock options and other issuance of Common Shares	$ 0		$ 0
Stock-based compensation, net of taxes paid from shares withheld from employees related to net share settlements	1,562	$ 1,450	1,562	1,450
Dividend equivalent rights on stock-based awards not paid in cash	154	143	$ 154	$ 143
Deduct:
Dividends on Common Shares	56,356	27,000			56,356	27,000
Dividend equivalent rights on stock-based awards	$ 154	$ 143			154	143
Ending Balance (in shares) at Dec. 31, 2022	36,962,241	170	36,962,000	170
Ending Balance at Dec. 31, 2022	$ 709,549	$ 643,906	$ 260,158	$ 358,123	449,391	285,783
Add:
Net Income	$ 124,921	$ 102,708			124,921	102,708
Exercise of stock options and other issuance of Common Shares	18,371	1	19,000	1
Exercise of stock options and other issuance of Common Shares	$ 0	$ 10,000	$ 0	$ 10,000
Stock-based compensation, net of taxes paid from shares withheld from employees related to net share settlements	2,834	2,614	2,834	2,614
Dividend equivalent rights on stock-based awards not paid in cash	187	172	$ 187	$ 172
Deduct:
Dividends on Common Shares	61,195	55,400			61,195	55,400
Dividend equivalent rights on stock-based awards	$ 187	$ 172			187	172
Ending Balance (in shares) at Dec. 31, 2023	36,980,612	171	36,981,000	171
Ending Balance at Dec. 31, 2023	$ 776,109	$ 703,828	$ 263,179	$ 370,909	$ 512,930	$ 332,919