Financial Instruments And Investments (Long-Term and Short-Term Borrowings Under the RCF - Narratives) (Details) (USD $) In Millions, unless otherwise specified	Sep. 30, 2013 Nuclear Fuel Financing	Dec. 31, 2012 Nuclear Fuel Financing	Sep. 30, 2013 Working Capital and General Purpose	Dec. 31, 2012 Working Capital and General Purpose	Aug. 18, 2010 Rgrt Senior Notes [Member]
Financial Instruments and Investments [Line Items]
Debt Instrument, Face Amount					$ 110
Line of Credit Facility, Amount Outstanding	$ 15.5	$ 22.2	$ 0	$ 0