Income Taxes	9 Months Ended
Sep. 30, 2014
Income Tax Disclosure [Abstract]
INCOME TAXES	Income Taxes SJW Corp. accounts for income taxes using the asset and liability method. Deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases. Measurement of the deferred tax assets and liabilities is at enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in the period that includes the enactment date. In the second quarter of 2014, SJW Corp. recorded $880 in State of California enterprise zone sales and use taxes credits related to tax years 2008 through 2012. On September 13, 2013, the Department of Treasury and the Internal Revenue Service issued final tangible property regulations under provisions that generally are intended to simplify, clarify and make more administrable the 2011 temporary and proposed tangible property regulations. These regulations broadly apply to amounts to acquire, produce or improve tangible property, as well as dispositions of such property and provide criteria for determining whether such amounts can be deducted or should be capitalized as part of the asset. The final regulations generally are effective for tax years beginning on or after January 1, 2014. During the third quarter of 2014, management completed its evaluation of the capitalization elections under the new regulations in order to establish its method of complying with the new regulations and record the impact in the consolidated financial statements. To comply with the new regulations, SJW Corp. will apply the accounting method change in its 2014 tax returns for the expensing of certain utility asset improvement costs for tax purposes as of December 31, 2013 that were previously being capitalized for book and tax purposes. As of September 30, 2014, the estimated 2014 federal and state repairs and maintenance deduction under the new methodology was $19,395, resulting in an estimated $5,091 Federal deferred tax liability and a state income tax benefit of $853. During the third quarter of 2014, SJW Corp. also completed a detailed analysis of the repairs and maintenance deduction related to 2013 and prior years, and recorded the estimated federal and state impact in the consolidated financial statements as of September 30, 2014. SJW Corp.'s Internal Revenue Code (“IRC”) §481(a) adjustment for Federal purposes was estimated to be $41,171 and resulted in a $14,410 deferred tax liability as of September 30, 2014. SJW Corp.'s IRC §481(a) adjustment for state purposes was estimated to be $83,524 and resulted in a $4,799 reduction to state income tax expense for the three and nine months ended September 30, 2014.

Income Taxes

SJW Corp. accounts for income taxes using the asset and liability method. Deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases. Measurement of the deferred tax assets and liabilities is at enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in the period that includes the enactment date.

In the second quarter of 2014, SJW Corp. recorded $880 in State of California enterprise zone sales and use taxes credits related to tax years 2008 through 2012.

On September 13, 2013, the Department of Treasury and the Internal Revenue Service issued final tangible property regulations under provisions that generally are intended to simplify, clarify and make more administrable the 2011 temporary and proposed tangible property regulations. These regulations broadly apply to amounts to acquire, produce or improve tangible property, as well as dispositions of such property and provide criteria for determining whether such amounts can be deducted or should be capitalized as part of the asset. The final regulations generally are effective for tax years beginning on or after January 1, 2014. During the third quarter of 2014, management completed its evaluation of the capitalization elections under the new regulations in order to establish its method of complying with the new regulations and record the impact in the consolidated financial statements. To comply with the new regulations, SJW Corp. will apply the accounting method change in its 2014 tax returns for the expensing of certain utility asset improvement costs for tax purposes as of December 31, 2013 that were previously being capitalized for book and tax purposes. As of September 30, 2014, the estimated 2014 federal and state repairs and maintenance deduction under the new methodology was $19,395, resulting in an estimated $5,091 Federal deferred tax liability and a state income tax benefit of $853. During the third quarter of 2014, SJW Corp. also completed a detailed analysis of the repairs and maintenance deduction related to 2013 and prior years, and recorded the estimated federal and state impact in the consolidated financial statements as of September 30, 2014. SJW Corp.'s Internal Revenue Code (“IRC”) §481(a) adjustment for Federal purposes was estimated to be $41,171 and resulted in a $14,410 deferred tax liability as of September 30, 2014. SJW Corp.'s IRC §481(a) adjustment for state purposes was estimated to be $83,524 and resulted in a $4,799 reduction to state income tax expense for the three and nine months ended September 30, 2014.