Regulatory Matters 6 (Details)	1 Months Ended	12 Months Ended
	Dec. 31, 2012 renewable_energy	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Jun. 30, 2019 USD ($)
Regulatory matters:
Regulatory asset authorized under settlement		$ 2,700,000
Cost of Capital, Proceeding for Water Regions [Member]
Regulatory matters:
Weighted Cost of Capital Percent		8.34%
Settlement Agreement Proposed Authorized Return on Equity Percentage		9.43%
GSWC
Regulatory matters:
Net regulatory assets		$ (2,450,000)	$ (28,340,000)
GSWC | Renewables Portfolio Standard [Member]
Regulatory matters:
Derivative, Term of Contract	10 years
Number of renewable energy credits that would be purchased | renewable_energy	578,000
Provision for Other Losses		$ 0
GSWC | Cost of Capital, Proceeding for Water Regions [Member]
Regulatory matters:
Return on Equity Percentage		8.90%
Weighted Cost of Capital Percent		7.91%
GSWC | Other Regulatory Assets (Liabilities) [Member]
Regulatory matters:
Net regulatory assets				$ 1,100,000
Electric general rate case [Member] [Member] | Revenues retroactive due to GRC delay [Member]
Regulatory matters:
Regulatory adjustment			2,300,000
Electric Service Utility Operations [Member] | Electric general rate case [Member] [Member]
Regulatory matters:
Return on Equity Percentage		9.60%
Settlement Agreement Proposed Authorized Return on Equity Percentage		9.95%
Various refunds to customers
Regulatory matters:
Decrease in revenues requirement to reflect the newly adopted Cost of Capital for GSWC		$ 982,000
Various refunds to customers | GSWC
Regulatory matters:
Net regulatory assets		$ (8,478,000)	$ (7,517,000)
Water Service Utility Operations [Member]
Regulatory matters:
Number of parties		3
Electric Service Utility Operations [Member]
Regulatory matters:
Number of parties		2