Regulatory Matters: CPUC Rehearing Matter and Procurement Audits (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2018 USD ($)
Revenue Subject to Refund
Regulatory matters:
Decrease in revenues requirement to reflect the newly adopted Cost of Capital for GSWC	$ 780,000
Cost of Capital, Proceeding for Water Regions
Regulatory matters:
Return on equity percentage	9.40%
Weighted cost of capital percent	8.30%
GOLDEN STATE WATER COMPANY | Revenue Subject to Refund
Regulatory matters:
Decrease in revenues requirement to reflect the newly adopted Cost of Capital for GSWC	$ 3,600
GOLDEN STATE WATER COMPANY | Revenue Subject to Refund
Regulatory matters:
Adjustments recorded to revalue deferred taxes as a result of the tax cut and job act of 2017 impact	$ 2,300
GOLDEN STATE WATER COMPANY | Cost of Capital, Proceeding for Water Regions
Regulatory matters:
Return on equity percentage	8.90%
Weighted cost of capital percent	7.90%
Electric Service Utility Operations | Revenue Subject to Refund
Regulatory matters:
Adjustments recorded to revalue deferred taxes as a result of the tax cut and job act of 2017 impact	$ 335