Capitalization	12 Months Ended
Dec. 31, 2016
Equity [Abstract]
CAPITALIZATION	Capitalization SJW Group is authorized to issue 36,000,000 shares of common stock of $0.001 par value per share. Prior to the reincorporation on November 15, 2016, discussed in Note 1, “Summary of Significant Accounting Policies,” SJW Corp. was authorized to issue 36,000,000 shares of common stock of $0.521 par value per share. At December 31, 2016 and 2015, 20,456,225 and 20,381,949, respectively, shares of common stock were issued and outstanding. In connection with the change of SJW Group’s common stock par value, SJW Group has recast stockholder’s equity in the Consolidated Balance Sheet as of December 31, 2015 and Consolidated Statements of Changes in Stockholders’ Equity for the years ended December 31, 2015 and 2014 to reflect the reincorporation. There were no changes to the historical number of shares issued and outstanding or earnings per share as a result of the reincorporation. At December 31, 2016, 1,000,000 shares of preferred stock of $0.001 par value per share were authorized for SJW Group. Prior to reincorporation and merger on November 15, 2016, SJW Group had 176,407 authorized shares of preferred stock of $25 par value per share. At December 31, 2016 and 2015, no shares of preferred stock were issued or outstanding.

Capitalization

12 Months Ended

Dec. 31, 2016

Capitalization

SJW Group is authorized to issue 36,000,000 shares of common stock of $0.001 par value per share. Prior to the reincorporation on November 15, 2016, discussed in Note 1, “Summary of Significant Accounting Policies,” SJW Corp. was authorized to issue 36,000,000 shares of common stock of $0.521 par value per share. At December 31, 2016 and 2015, 20,456,225 and 20,381,949, respectively, shares of common stock were issued and outstanding. In connection with the change of SJW Group’s common stock par value, SJW Group has recast stockholder’s equity in the Consolidated Balance Sheet as of December 31, 2015 and Consolidated Statements of Changes in Stockholders’ Equity for the years ended December 31, 2015 and 2014 to reflect the reincorporation. There were no changes to the historical number of shares issued and outstanding or earnings per share as a result of the reincorporation.

At December 31, 2016, 1,000,000 shares of preferred stock of $0.001 par value per share were authorized for SJW Group. Prior to reincorporation and merger on November 15, 2016, SJW Group had 176,407 authorized shares of preferred stock of $25 par value per share. At December 31, 2016 and 2015, no shares of preferred stock were issued or outstanding.