Capitalization	12 Months Ended
Dec. 31, 2011
Capitalization [Abstract]
Stockholders' Equity Note Disclosure [Text Block]	Capitalization SJW Corp. is authorized to issue 36,000,000 shares of common stock of $0.521 par value per share. At December 31, 2011 and 2010, 18,592,827 and 18,551,540, respectively, shares of common stock were issued and outstanding. At December 31, 2011 and 2010, 176,407 shares of preferred stock of $25 par value per share were authorized and none were outstanding.

Capitalization

12 Months Ended

Dec. 31, 2011

Stockholders' Equity Note Disclosure [Text Block]

Capitalization

SJW Corp. is authorized to issue 36,000,000 shares of common stock of $0.521 par value per share. At December 31, 2011 and 2010, 18,592,827 and 18,551,540, respectively, shares of common stock were issued and outstanding.

At December 31, 2011 and 2010, 176,407 shares of preferred stock of $25 par value per share were authorized and none were outstanding.

- Definition

The entire disclosure for shareholders' equity, comprised of portions attributable to the parent entity and noncontrolling interest, if any, including other comprehensive income (as applicable). Including, but not limited to: (1) balances of common stock, preferred stock, additional paid-in capital, other capital and retained earnings; (2) accumulated balance for each classification of other comprehensive income and total amount of comprehensive income; (3) amount and nature of changes in separate accounts, including the number of shares authorized and outstanding, number of shares issued upon exercise and conversion, and for other comprehensive income, the adjustments for reclassifications to net income; (4) rights and privileges of each class of stock authorized; (5) basis of treasury stock, if other than cost, and amounts paid and accounting treatment for treasury stock purchased significantly in excess of market; (6) dividends paid or payable per share and in the aggregate for each class of stock for each period presented; (7) dividend restrictions and accumulated preferred dividends in arrears (in aggregate and per share amount); (8) retained earnings appropriations or restrictions, such as dividend restrictions; (9) impact of change in accounting principle, initial adoption of new accounting principle and correction of an error in previously issued financial statements; (10) shares held in trust for Employee Stock Ownership Plan (ESOP); (11) deferred compensation related to issuance of capital stock; (12) note received for issuance of stock; (13) unamortized discount on shares; (14) description, terms, and number of warrants or rights outstanding; (15) shares under subscription and subscription receivables, effective date of new retained earnings after quasi-reorganization and deficit eliminated by quasi-reorganization and, for a period of at least ten years after the effective date, the point in time from which the new retained dates; and (16) retroactive effective of subsequent change in capital structure.

+ References

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+ Details