Fair Value Measurement (Tables)

9 Months Ended

Sep. 30, 2014

Fair Value Disclosures [Abstract]

Fair Value, Assets Measured on Recurring Basis

The following table summarizes the fair value of the SJW Corps.'s investment in California Water Service Group as of September 30, 2014 and December 31, 2013:

	Fair Value Measurements at September 30, 2014
			Quoted Prices in Active Markets for Identical Assets	Significant Observable Inputs	Significant Unobservable Inputs
	Total		(Level 1)	(Level 2)	(Level 3)
Assets:
Investment in California Water Service Group	$	5,815	5,815	—	—
	Fair Value Measurements at December 31, 2013
			Quoted Prices in Active Markets for Identical Assets	Significant Observable Inputs	Significant Unobservable Inputs
	Total		(Level 1)	(Level 2)	(Level 3)
Assets:
Investment in California Water Service Group	$	8,885	8,885	—	—