Dividend Limitations (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)
Dividend limitations
Common shareholder’s equity	$ 776,109	$ 709,549	$ 685,947	$ 641,673
GSWC
Dividend limitations
Ratio of Indebtedness to Net Capital	0.4956
Dividends paid	$ 55,400	27,000	38,300
Common shareholder’s equity	$ 703,828	$ 643,906	$ 615,686	$ 583,298
GSWC | Maximum
Dividend limitations
Ratio of Indebtedness to Net Capital	0.6667