General	3 Months Ended
Mar. 31, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
GENERAL	General In the opinion of management, the accompanying unaudited condensed consolidated financial statements reflect all adjustments (consisting only of normal, recurring adjustments) necessary for a fair presentation of the results for the interim periods. The unaudited interim financial information has been prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”) and in accordance with the instructions for Form 10-Q and Rule 10-01 of Regulation S-X promulgated by the Securities and Exchange Commission (the “SEC”). The Notes to Consolidated Financial Statements in SJW Corp.'s 2014 Annual Report on Form 10-K should be read with the accompanying unaudited condensed consolidated financial statements. Water sales are seasonal in nature and influenced by weather conditions. The timing of precipitation and climatic conditions can cause seasonal water consumption by customers to vary significantly. Due to the seasonal nature of the water business, the operating results for interim periods are not indicative of the operating results for a 12-month period. Revenue is generally higher in the warm, dry summer months when water usage and sales are greater, and lower in the winter months when cooler temperatures and increased rainfall curtail water usage and sales. In response to the ongoing drought in California, on March 17, 2015, the State Water Resources Control Board (“State Water Board”) adopted an expanded emergency conservation regulation that became effective on March 27, 2015. The regulation prohibits certain outdoor water uses for all Californians and also places water usage restrictions on businesses in the restaurant and hospitality sectors. On March 25, 2015, the Santa Clara Valley Water District (“SCVWD”) increased their conservation target from 20% to 30% through the end of 2015. On April 1, 2015, Governor Edmund G. Brown Jr. issued an executive order imposing restrictions to achieve a statewide 25% reduction in potable urban water usage through February 28, 2016 based on 2013 usage. On April 9, 2015, the California Public Utilities Commission (“CPUC”) issued a resolution ordering its regulated water utilities to comply with the State Water Board's emergency conservation regulation, conduct additional customer outreach and implement restrictions of outdoor water use. Additional guidance from the State Water Board in response to the Governor's Executive Order is anticipated in early May. San Jose Water Company is currently working to comply with the various rules and regulations and is also working with local governments as well as the SCVWD to communicate consistent messages to the public. Effective March 31, 2014, San Jose Water Company received approval from the CPUC for a Mandatory Conservation Revenue Adjustment Memorandum Account (“MCRAMA”) to track any revenue shortfall and a Mandatory Conservation Memorandum Account (“MCMA”) to track operational and administrative costs associated with implementation of the 2014 20% SCVWD conservation goal. San Jose Water Company will record the lost revenue captured in the MCRAMA and MCMA regulatory accounts once probability of recovery can be determined and collection can be assured within 24 months after the end of the fiscal year in which the revenue is recorded. For further discussion, please see Note 8 and Note 9. Basic earnings per share is calculated using income available to common shareholders, divided by the weighted average number of shares outstanding during the period. Diluted earnings per share is calculated using income available to common shareholders divided by the weighted average number of shares of common stock including both shares outstanding and shares potentially issuable in connection with deferred restricted common stock awards under SJW Corp.'s Long-Term Incentive Plan (as amended, the “Incentive Plan”) and shares potentially issuable under the 2014 Employee Stock Purchase Plan (“ESPP”). For the three months ended March 31, 2015 and 2014, 118 and 449 anti-dilutive restricted common stock units were excluded from the dilutive earnings per share calculation, respectively. A portion of depreciation expense is allocated to administrative and general expense. For the three months ended March 31, 2015 and 2014, the amounts allocated to administrative and general expense were $399 and $396, respectively.

General

In the opinion of management, the accompanying unaudited condensed consolidated financial statements reflect all adjustments (consisting only of normal, recurring adjustments) necessary for a fair presentation of the results for the interim periods.

The unaudited interim financial information has been prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”) and in accordance with the instructions for Form 10-Q and Rule 10-01 of Regulation S-X promulgated by the Securities and Exchange Commission (the “SEC”). The Notes to Consolidated Financial Statements in SJW Corp.'s 2014 Annual Report on Form 10-K should be read with the accompanying unaudited condensed consolidated financial statements.

Water sales are seasonal in nature and influenced by weather conditions. The timing of precipitation and climatic conditions can cause seasonal water consumption by customers to vary significantly. Due to the seasonal nature of the water business, the operating results for interim periods are not indicative of the operating results for a 12-month period. Revenue is generally higher in the warm, dry summer months when water usage and sales are greater, and lower in the winter months when cooler temperatures and increased rainfall curtail water usage and sales.

In response to the ongoing drought in California, on March 17, 2015, the State Water Resources Control Board (“State Water Board”) adopted an expanded emergency conservation regulation that became effective on March 27, 2015. The regulation prohibits certain outdoor water uses for all Californians and also places water usage restrictions on businesses in the restaurant and hospitality sectors. On March 25, 2015, the Santa Clara Valley Water District (“SCVWD”) increased their conservation target from 20% to 30% through the end of 2015. On April 1, 2015, Governor Edmund G. Brown Jr. issued an executive order imposing restrictions to achieve a statewide 25% reduction in potable urban water usage through February 28, 2016 based on 2013 usage. On April 9, 2015, the California Public Utilities Commission (“CPUC”) issued a resolution ordering its regulated water utilities to comply with the State Water Board's emergency conservation regulation, conduct additional customer outreach and implement restrictions of outdoor water use. Additional guidance from the State Water Board in response to the Governor's Executive Order is anticipated in early May. San Jose Water Company is currently working to comply with the various rules and regulations and is also working with local governments as well as the SCVWD to communicate consistent messages to the public.

Effective March 31, 2014, San Jose Water Company received approval from the CPUC for a Mandatory Conservation Revenue Adjustment Memorandum Account (“MCRAMA”) to track any revenue shortfall and a Mandatory Conservation Memorandum Account (“MCMA”) to track operational and administrative costs associated with implementation of the 2014 20% SCVWD conservation goal. San Jose Water Company will record the lost revenue captured in the MCRAMA and MCMA regulatory accounts once probability of recovery can be determined and collection can be assured within 24 months after the end of the fiscal year in which the revenue is recorded. For further discussion, please see Note 8 and Note 9.

Basic earnings per share is calculated using income available to common shareholders, divided by the weighted average number of shares outstanding during the period. Diluted earnings per share is calculated using income available to common shareholders divided by the weighted average number of shares of common stock including both shares outstanding and shares potentially issuable in connection with deferred restricted common stock awards under SJW Corp.'s Long-Term Incentive Plan (as amended, the “Incentive Plan”) and shares potentially issuable under the 2014 Employee Stock Purchase Plan (“ESPP”). For the three months ended March 31, 2015 and 2014, 118 and 449 anti-dilutive restricted common stock units were excluded from the dilutive earnings per share calculation, respectively.

A portion of depreciation expense is allocated to administrative and general expense. For the three months ended March 31, 2015 and 2014, the amounts allocated to administrative and general expense were $399 and $396, respectively.