Regulatory Matters (Details 10) (GSWC, Cost of Capital Proceeding for Water Regions)	12 Months Ended
	Dec. 31, 2013	Sep. 30, 2012	Oct. 02, 2012	Jul. 31, 2012
Regulatory matters:
Authorized return on equity percentage			9.43%	9.99%
Period of cost of capital proceedings considered for adjustment of R O E and rate of return on rate base	3 years
Difference adjustment in ROE (as a percent)	50.00%
Decrease in Moody's rate from benchmark (as a percent)		1.12%
Decrease in ROE (as a percent)	0.56%
Proposed authorized ROE under the settlement agreement (as a percent)				9.43%
Minimum
Regulatory matters:
Change in average of the Moody's Aa utility bond rate (as a percent)	1.00%