Business Segments: (Details 2) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Details of reportable segment
Total utility plant	$ 1,479,110	$ 1,378,366	$ 1,479,110	$ 1,378,366	$ 1,415,705
Other assets	247,308	226,015	247,308	226,015
Total Assets	1,726,418	1,604,381	1,726,418	1,604,381	1,641,331
GOLDEN STATE WATER COMPANY
Details of reportable segment
Depreciation on transportation equipment	84	$ 80	249	$ 234
Total utility plant	1,373,323		1,373,323		1,394,742
Total Assets	$ 1,505,751		$ 1,505,751		$ 1,522,454