Basis of Presentation (Details) (USD $)	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2013 retail_customers	Sep. 30, 2012	Sep. 30, 2013 retail_customers	Sep. 30, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Basis of Presentation [Abstract]
Number of Retail Customers	835,540		835,540
Decoupling Mechanism Deferrals, Net		$ 1,000,000	$ (5,000,000)	$ 1,000,000
Contribution to the voluntary employees’ beneficiary association trust				2,000,000
Renewable adjustment clause deferrals				1,000,000
Other Comprehensive Income	0	0	0	0
revenue overstatment	$ 9,000,000			$ 3,000,000	$ 3,000,000	$ 2,000,000	$ 1,000,000