Contingencies:	9 Months Ended
Sep. 30, 2014
Commitments and Contingencies Disclosure [Abstract]
Contingencies	Contingencies: 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: (i) that the owner of utility property may contest whether the condemnation is actually necessary and in the public interest, and (ii) that the owner is entitled to receive the fair market value of its property if the property is ultimately taken. Claremont System: The City of Claremont ("Claremont" or "the City") located in GSWC’s Region III, has expressed various concerns to GSWC about rates charged by GSWC and the effectiveness of the CPUC’s rate-setting procedures. In November 2012 and again in September 2013, Claremont made offers to acquire GSWC’s water system servicing Claremont. GSWC rejected both offers and informed the City that the system is not for sale. Claremont continues to express a desire to potentially take the system by eminent domain. On July 31, 2014, the City passed a resolution calling for a special election to be held November 4, 2014 for the purpose of authorizing the issuance of $135.0 million in water revenue bonds by the City to finance the acquisition of the system. GSWC serves approximately 11,000 customers in Claremont. Ojai System: In April 2011, an organization called Ojai FLOW ("Friends of Locally Owned Water") started a local campaign for the Casitas Municipal Water District ("CMWD") to purchase GSWC’s Ojai water system. In March 2013, CMWD passed resolutions authorizing the establishment of a Community Facilities District, an entity authorized pursuant to the Mello-Roos Community Facilities District Act of 1982 ("Mello-Roos Act") and the issuance of bonds to finance the potential acquisition of GSWC’s Ojai system by eminent domain. In August 2013, Ojai residents approved the levying of a special tax to satisfy the planned bond obligations. GSWC filed a petition in the Superior Court, Ventura County, which, among other things, challenged the legality of CMWD’s effort to utilize the Mello-Roos Act to acquire property by eminent domain and to fund legal and expert costs of the planned condemnation. Ojai FLOW members filed a motion with the Superior Court asking that all residents of GSWC’s Ojai service area be certified as class defendants in GSWC's pending action. They contend that the class would later be entitled to sue GSWC for damages if GSWC's challenge is denied. Without deciding whether such a lawsuit would be permitted, the Court granted the motion for class certification. On March 13, 2014, the Court denied GSWC's petition. On April 9, 2014, GSWC filed a Notice of Appeal. GSWC is unable to predict the outcome of the appeal at this time. GSWC serves approximately 3,000 customers in Ojai. Apple Valley System: In recent years the Town of Apple Valley has considered a potential condemnation of the water systems serving its area, including GSWC's Apple Valley system. In August 2014, Apple Valley's Town Council issued a request for proposal for an updated feasibility study on the potential acquisition of the water systems. GSWC serves approximately 2,900 customers in the Town of Apple Valley. Artesia System: On October 13, 2014, the City of Artesia's City Council approved a request for a feasibility study on the potential acquisition of GSWC's water system in Artesia. GSWC serves approximately 3,300 customers in Artesia. Environmental Clean-Up and Remediation: GSWC has been involved in environmental remediation and clean-up at a plant site ("Chadron Plant") that contained an underground storage tank which was used to store gasoline for its vehicles. This 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 this site. Recent analysis indicates that offsite monitoring wells may also be necessary to document effectiveness of remediation. As of September 30, 2014, the total spent to clean-up and remediate GSWC’s plant facility was approximately $4.3 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 September 30, 2014, GSWC has a regulatory asset and an accrued liability for the estimated additional cost of $1.4 million to complete the clean-up 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 also 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. Management believes that rate recovery, proper insurance coverage and reserves are in place to insure against property, general liability and workers’ compensation claims incurred in the ordinary course of business. Registrant is unable to predict an estimate of the loss, if any, resulting from any pending suits or administrative proceedings.

Contingencies:

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: (i) that the owner of utility property may contest whether the condemnation is actually necessary and in the public interest, and (ii) that the owner is entitled to receive the fair market value of its property if the property is ultimately taken.

Claremont System:

The City of Claremont ("Claremont" or "the City") located in GSWC’s Region III, has expressed various concerns to GSWC about rates charged by GSWC and the effectiveness of the CPUC’s rate-setting procedures. In November 2012 and again in September 2013, Claremont made offers to acquire GSWC’s water system servicing Claremont. GSWC rejected both offers and informed the City that the system is not for sale. Claremont continues to express a desire to potentially take the system by eminent domain.

On July 31, 2014, the City passed a resolution calling for a special election to be held November 4, 2014 for the purpose of authorizing the issuance of $135.0 million in water revenue bonds by the City to finance the acquisition of the system. GSWC serves approximately 11,000 customers in Claremont.

Ojai System:

In April 2011, an organization called Ojai FLOW ("Friends of Locally Owned Water") started a local campaign for the Casitas Municipal Water District ("CMWD") to purchase GSWC’s Ojai water system. In March 2013, CMWD passed resolutions authorizing the establishment of a Community Facilities District, an entity authorized pursuant to the Mello-Roos Community Facilities District Act of 1982 ("Mello-Roos Act") and the issuance of bonds to finance the potential acquisition of GSWC’s Ojai system by eminent domain. In August 2013, Ojai residents approved the levying of a special tax to satisfy the planned bond obligations. GSWC filed a petition in the Superior Court, Ventura County, which, among other things, challenged the legality of CMWD’s effort to utilize the Mello-Roos Act to acquire property by eminent domain and to fund legal and expert costs of the planned condemnation. Ojai FLOW members filed a motion with the Superior Court asking that all residents of GSWC’s Ojai service area be certified as class defendants in GSWC's pending action. They contend that the class would later be entitled to sue GSWC for damages if GSWC's challenge is denied. Without deciding whether such a lawsuit would be permitted, the Court granted the motion for class certification. On March 13, 2014, the Court denied GSWC's petition. On April 9, 2014, GSWC filed a Notice of Appeal. GSWC is unable to predict the outcome of the appeal at this time. GSWC serves approximately 3,000 customers in Ojai.

Apple Valley System:

In recent years the Town of Apple Valley has considered a potential condemnation of the water systems serving its area, including GSWC's Apple Valley system. In August 2014, Apple Valley's Town Council issued a request for proposal for an updated feasibility study on the potential acquisition of the water systems. GSWC serves approximately 2,900 customers in the Town of Apple Valley.

Artesia System:

On October 13, 2014, the City of Artesia's City Council approved a request for a feasibility study on the potential acquisition of GSWC's water system in Artesia. GSWC serves approximately 3,300 customers in Artesia.

Environmental Clean-Up and Remediation:

GSWC has been involved in environmental remediation and clean-up at a plant site ("Chadron Plant") that contained an underground storage tank which was used to store gasoline for its vehicles. This 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 this site. Recent analysis indicates that offsite monitoring wells may also be necessary to document effectiveness of remediation.

As of September 30, 2014, the total spent to clean-up and remediate GSWC’s plant facility was approximately $4.3 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 September 30, 2014, GSWC has a regulatory asset and an accrued liability for the estimated additional cost of $1.4 million to complete the clean-up 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 also 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. Management believes that rate recovery, proper insurance coverage and reserves are in place to insure against property, general liability and workers’ compensation claims incurred in the ordinary course of business. Registrant is unable to predict an estimate of the loss, if any, resulting from any pending suits or administrative proceedings.