Regulatory Matters: CPUC Rehearing Matter and Procurement Audits (Details) (USD $)	1 Months Ended	12 Months Ended		1 Months Ended
	Dec. 31, 2011 Audit	Dec. 31, 2012	Dec. 31, 2010	Jul. 31, 2011 GSWC La Serena Plant Improvement Project CPUC Rehearing Matter
Regulatory matters:
Costs included in rehearing matter				$ 3,500,000
Disallowed costs and related refunds		$ 416,000	$ 2,200,000
Separate independent audits	3
Separate independent audits, period of years after settlement date	10 years