Contingencies and Gain on Sale of Assets	6 Months Ended
Jun. 30, 2018
Commitments and Contingencies Disclosure [Abstract]
Contingencies and Gain on Sale of Assets	Contingencies and Gain on Sale of Assets Condemnation of Properties: The laws of the State of California provide for the acquisition of public utility property by governmental agencies through their power of eminent domain, also known as condemnation, where doing so is necessary and in the public interest. In addition, these laws provide that the owner of utility property (i) may contest whether the condemnation is necessary and in the public interest, and (ii) is entitled to receive the fair market value of its property if the property is ultimately taken. Ojai Water System and Gain on Sale of Assets: Pursuant to a settlement agreement, on June 8, 2017, Casitas Municipal Water District (“Casitas”) acquired the operating assets of GSWC’s 2,900-connection Ojai water system by eminent domain for $34.3 million in cash, including payments for customer receivables and regulatory assets. As a result of this transaction, GSWC recorded a pretax gain of $8.3 million on the sale of the Ojai water system during the second quarter of 2017. The terms of the settlement agreement resolved the eminent domain action and dismissed all claims against GSWC brought by Casitas and another third party. Environmental Clean-Up and Remediation: GSWC has been involved in environmental remediation and cleanup at a plant site ("Chadron Plant") that contained an underground storage tank that had been used to store gasoline for its vehicles. The tank was removed from the ground in July 1990 along with the dispenser and ancillary piping. Since then, GSWC has been involved in various remediation activities at the site. Analyses indicate that off-site monitoring wells may be necessary to document the effectiveness of remediation. As of June 30, 2018, the total spent to clean-up and remediate GSWC’s plant facility was approximately $5.5 million, of which $1.5 million has been paid by the State of California Underground Storage Tank Fund. Amounts paid by GSWC have been included in rate base and approved by the CPUC for recovery. As of June 30, 2018, GSWC has a regulatory asset and an accrued liability for the estimated additional cost of $1.3 million to complete the cleanup at the site. The estimate includes costs for two years of continued activities of groundwater cleanup and monitoring, future soil treatment and site-closure-related activities. The ultimate cost may vary as there are many unknowns in remediation of underground gasoline spills and this is an estimate based on currently available information. Management believes it is probable that the estimated additional costs will be approved in rate base by the CPUC. Other Litigation: Registrant is also subject to other ordinary routine litigation incidental to its business, some of which may include claims for compensatory and punitive damages. Management believes that rate recovery, proper insurance coverage and reserves are in place to insure against, among other things, property, general liability, employment, and workers’ compensation claims incurred in the ordinary course of business. Insurance coverage may not cover certain claims involving punitive damages. However, Registrant does not believe the outcome from any pending suits or administrative proceedings will have a material effect on Registrant's consolidated results of operations, financial position or cash flows.

Contingencies and Gain on Sale of Assets

Condemnation of Properties:

The laws of the State of California provide for the acquisition of public utility property by governmental agencies through their power of eminent domain, also known as condemnation, where doing so is necessary and in the public interest. In addition, these laws provide that the owner of utility property (i) may contest whether the condemnation is necessary and in the public interest, and (ii) is entitled to receive the fair market value of its property if the property is ultimately taken.

Ojai Water System and Gain on Sale of Assets:

Pursuant to a settlement agreement, on June 8, 2017, Casitas Municipal Water District (“Casitas”) acquired the operating assets of GSWC’s 2,900-connection Ojai water system by eminent domain for $34.3 million in cash, including payments for customer receivables and regulatory assets. As a result of this transaction, GSWC recorded a pretax gain of $8.3 million on the sale of the Ojai water system during the second quarter of 2017. The terms of the settlement agreement resolved the eminent domain action and dismissed all claims against GSWC brought by Casitas and another third party.

Environmental Clean-Up and Remediation:

GSWC has been involved in environmental remediation and cleanup at a plant site ("Chadron Plant") that contained an underground storage tank that had been used to store gasoline for its vehicles. The tank was removed from the ground in July 1990 along with the dispenser and ancillary piping. Since then, GSWC has been involved in various remediation activities at the site. Analyses indicate that off-site monitoring wells may be necessary to document the effectiveness of remediation.

As of June 30, 2018, the total spent to clean-up and remediate GSWC’s plant facility was approximately $5.5 million, of which $1.5 million has been paid by the State of California Underground Storage Tank Fund. Amounts paid by GSWC have been included in rate base and approved by the CPUC for recovery. As of June 30, 2018, GSWC has a regulatory asset and an accrued liability for the estimated additional cost of $1.3 million to complete the cleanup at the site. The estimate includes costs for two years of continued activities of groundwater cleanup and monitoring, future soil treatment and site-closure-related activities. The ultimate cost may vary as there are many unknowns in remediation of underground gasoline spills and this is an estimate based on currently available information. Management believes it is probable that the estimated additional costs will be approved in rate base by the CPUC.

Other Litigation:

Registrant is also subject to other ordinary routine litigation incidental to its business, some of which may include claims for compensatory and punitive damages. Management believes that rate recovery, proper insurance coverage and reserves are in place to insure against, among other things, property, general liability, employment, and workers’ compensation claims incurred in the ordinary course of business. Insurance coverage may not cover certain claims involving punitive damages. However, Registrant does not believe the outcome from any pending suits or administrative proceedings will have a material effect on Registrant's consolidated results of operations, financial position or cash flows.