Fair Value Measurements (Details Textuals) (USD $) In Millions, unless otherwise specified					12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2013 FES	Dec. 31, 2012 FES	Dec. 31, 2013 NUG contracts
Fair Value of Financial Instruments [Line Items]
Period of future observable data to determine contract price					3 years
Investment excludes Receivables, Payables and Accrued income	$ 10	$ 110	$ 9	$ 94
Cash balance excluded from available for sale securities	204	326	135	196
Investments not required to be disclosed	$ 636	$ 644