Commitment and Contingencies	6 Months Ended
Jun. 30, 2016
Commitments and Contingencies Disclosure [Abstract]
Commitment and Contingencies	Commitment and Contingencies Commitments The Company has significant commitments to lease certain office spaces and water systems and to purchase water from water wholesalers. These commitments are described in Form 10-K for the year ended December 31, 2015. As of June 30, 2016, there were no significant changes from December 31, 2015. Contingencies Groundwater Contamination The Company has undertaken litigation against third parties to recover past and anticipated costs related to groundwater contamination in our service areas. The cost of litigation is expensed as incurred and any settlement is first offset against such costs. The CPUC’s general policy requires all proceeds from groundwater contamination litigation to be used first to pay transactional expenses, then to make ratepayers whole for water treatment costs to comply with the CPUC’s water quality standards. The CPUC allows for a risk-based consideration of contamination proceeds which exceed the costs of the remediation described above and may result in some sharing of proceeds with the shareholder, determined on a case by case basis. The CPUC has authorized various memorandum accounts that allow the Company to track significant litigation costs to request recovery of these costs in future filings and uses of proceeds to comply with CPUC’s general policy. Legal Proceedings From time to time, the Company is involved in various disputes and litigation matters that arise in the ordinary course of business. The status of each significant matter is reviewed and assessed for potential financial exposure. If the potential loss from any claim or legal proceeding is considered probable and the amount of the range of loss can be estimated, a liability is accrued for the estimated loss in accordance with the accounting standards for contingencies. Legal proceedings are subject to uncertainties, and the outcomes are difficult to predict. Because of such uncertainties, accruals are based on the best information available at the time. While the outcome of these disputes and litigation matters cannot be predicted with any certainty, management does not believe when taking into account existing reserves the ultimate resolution of these matters will materially affect the Company’s financial position, results of operations, or cash flows. The Company recognized a liability of $3.4 million and $3.5 million for known legal matters as of June 30, 2016 and December 31, 2015, respectively. The cost of litigation is expensed as incurred and any settlement is first offset against such costs. Any settlement in excess of the cost to litigate is accounted for on a case by case basis, dependent on the nature of the settlement. On July 21, 2016, the San Francisco Bay Area Regional Water Quality Control Board (the Water Control Board) approved a settlement between Cal Water and the Water Control Board and California Department of Fish and Wildlife (Fish and Wildlife) to resolve purported complaints from the Water Control Board and Fish and Wildlife alleging Cal Water discharged approximately 8,207,560 gallons of drinking water into Polhemus Creek that was caused by an undetected crack in a large water main located 10 feet below ground in a remote area. The water was disinfected as required to meet all federal and state water quality standards and make it safe for human consumption. Drinking water, however, can be harmful to fish and the environment. As part of the settlement, Cal Water will replace 2,000 feet of 18-inch cast iron water main with new ductile iron main along Polhemus Road and Polhemus Creek in San Mateo. Cal Water will also conduct a streambed restoration project in San Mateo Creek to improve conditions in the creek for native fish. This work will be performed in coordination with the California Department of Fish and Wildlife. In addition to investing in these improvement projects, Cal Water will pay $504,519 to the Water Control Board and $20,000 to Fish and Wildlife. Under the terms of the settlement, Cal Water will be released from all claims unless it fails to complete the projects. The agreement contains no admission of wrongdoing.

Commitment and Contingencies

Commitments

The Company has significant commitments to lease certain office spaces and water systems and to purchase water from water wholesalers. These commitments are described in Form 10-K for the year ended December 31, 2015. As of June 30, 2016, there were no significant changes from December 31, 2015.

Contingencies

Groundwater Contamination

The Company has undertaken litigation against third parties to recover past and anticipated costs related to groundwater contamination in our service areas. The cost of litigation is expensed as incurred and any settlement is first offset against such costs. The CPUC’s general policy requires all proceeds from groundwater contamination litigation to be used first to pay transactional expenses, then to make ratepayers whole for water treatment costs to comply with the CPUC’s water quality standards. The CPUC allows for a risk-based consideration of contamination proceeds which exceed the costs of the remediation described above and may result in some sharing of proceeds with the shareholder, determined on a case by case basis. The CPUC has authorized various memorandum accounts that allow the Company to track significant litigation costs to request recovery of these costs in future filings and uses of proceeds to comply with CPUC’s general policy.

Legal Proceedings

From time to time, the Company is involved in various disputes and litigation matters that arise in the ordinary course of business. The status of each significant matter is reviewed and assessed for potential financial exposure. If the potential loss from any claim or legal proceeding is considered probable and the amount of the range of loss can be estimated, a liability is accrued for the estimated loss in accordance with the accounting standards for contingencies. Legal proceedings are subject to uncertainties, and the outcomes are difficult to predict. Because of such uncertainties, accruals are based on the best information available at the time. While the outcome of these disputes and litigation matters cannot be predicted with any certainty, management does not believe when taking into account existing reserves the ultimate resolution of these matters will materially affect the Company’s financial position, results of operations, or cash flows. The Company recognized a liability of $3.4 million and $3.5 million for known legal matters as of June 30, 2016 and December 31, 2015, respectively. The cost of litigation is expensed as incurred and any settlement is first offset against such costs. Any settlement in excess of the cost to litigate is accounted for on a case by case basis, dependent on the nature of the settlement.

On July 21, 2016, the San Francisco Bay Area Regional Water Quality Control Board (the Water Control Board) approved a settlement between Cal Water and the Water Control Board and California Department of Fish and Wildlife (Fish and Wildlife) to resolve purported complaints from the Water Control Board and Fish and Wildlife alleging Cal Water discharged approximately 8,207,560 gallons of drinking water into Polhemus Creek that was caused by an undetected crack in a large water main located 10 feet below ground in a remote area. The water was disinfected as required to meet all federal and state water quality standards and make it safe for human consumption. Drinking water, however, can be harmful to fish and the environment.

As part of the settlement, Cal Water will replace 2,000 feet of 18-inch cast iron water main with new ductile iron main along Polhemus Road and Polhemus Creek in San Mateo. Cal Water will also conduct a streambed restoration project in San Mateo Creek to improve conditions in the creek for native fish. This work will be performed in coordination with the California Department of Fish and Wildlife. In addition to investing in these improvement projects, Cal Water will pay $504,519 to the Water Control Board and $20,000 to Fish and Wildlife.

Under the terms of the settlement, Cal Water will be released from all claims unless it fails to complete the projects. The agreement contains no admission of wrongdoing.