Summary of Significant Accounting Policies (Revenue, Balancing and Memorandum Accounts) (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Revenue from External Customer [Line Items]
Regulated operating revenue, water surcharge	$ 4,605	$ 3,872	$ 3,741
San Jose Water Company [Member]
Revenue from External Customer [Line Items]
Nonregulated operating revenue	$ 6,145	$ 6,175	$ 5,882

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

No definition available.

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