Regulatory Matters: BVES General Rate Case and Renewables Portfolio Standard (Details) (GSWC, USD $)			1 Months Ended			9 Months Ended	1 Months Ended	3 Months Ended
	Sep. 30, 2013	Dec. 31, 2012	Mar. 31, 2013 BVES General Rate Case	Aug. 31, 2012 BVES General Rate Case	Mar. 31, 2012 BVES General Rate Case	Sep. 30, 2013 BVES General Rate Case	Dec. 31, 2012 Renewables Portfolio Standard RECs	Sep. 30, 2013 Renewables Portfolio Standard RECs
Regulatory matters:
Amount of retroactive ratemaking proposal included in DRA's recommendation to increase accumulated depreciation				$ 2,000,000
Net regulatory assets	173,498,000	176,015,000				1,900,000
Portion of deferred rate case costs required to be written off, if DRA prevails						50.00%
Provision for loss								0
Agreement period to purchase renewable energy credits							10 years
Purchased Renewable Energy Credits Number							582,000	116,000
Amount billed to customers as surcharges			$ 835,000		$ 1,200,000
Regulatory Asset Recovery Periods						12 months
Percentage of deferred rate case cost to be borne by shareholders						50.00%