Lines of Credit Narrative (Details) (USD $)							12 Months Ended
	Dec. 31, 2013 Unsecured Debt [Member] Wells Fargo [Member] SJW Corp. [Member]	Dec. 31, 2013 Revolving Credit Facility [Member]	Dec. 31, 2013 Revolving Credit Facility [Member] SJW Corp. [Member]	Dec. 31, 2012 Revolving Credit Facility [Member] SJW Corp. [Member]	Mar. 01, 2012 Revolving Credit Facility [Member] Wells Fargo [Member] SJW Corp., SJW Land Company [Member]	Mar. 01, 2012 Revolving Credit Facility [Member] Wells Fargo [Member] San Jose Water Company [Member]	Dec. 31, 2013 Standby Letters of Credit [Member] San Jose Water Company [Member] standy_letter_of_credit
Ratio of indebtedness to total capital	0.666
Aggregate amount of unsecured revolving credit facility		$ 90,000,000			$ 15,000,000	$ 75,000,000	$ 3,000,000
Number of standby letters of credit							2
Automatic renewal term of standby letters of credit							1 year
Aggregate outstanding balance on lines of credit			$ 22,400,000	$ 15,300,000
Line of Credit Facility, Interest Rate at Period End			1.29%	1.44%
Debt covenant interest charge maximum to net Income available to stockholders	1.75