Business Segments: (Details 2) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Details of reportable segment
Income tax expense (benefit)	$ 4,387	$ 14,307	$ 6,951	$ 21,162
Total utility plant	1,238,789	1,155,203	1,238,789	1,155,203	$ 1,204,992
Other assets	202,333	307,450	202,333	307,450
Total Assets	1,441,122	1,462,653	1,441,122	1,462,653	1,416,734
GOLDEN STATE WATER COMPANY
Details of reportable segment
Income tax expense (benefit)	4,214	12,149	6,329	18,422
Depreciation on transportation equipment	61	$ 59	121	$ 120
Total utility plant	1,227,371		1,227,371		1,197,940
Total Assets	$ 1,341,075		$ 1,341,075		$ 1,326,823