Derivative Financial Instruments (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended		1 Months Ended	6 Months Ended	1 Months Ended		3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012	Mar. 31, 2007 Level 3 Financing Inc. derivatives	Jun. 30, 2013 Level 3 Financing Inc. derivatives	Mar. 31, 2007 Level 3 Financing Inc. Interest Rate Swap, Agreement One	Mar. 31, 2007 Level 3 Financing Inc. Interest Rate Swap, Agreement Two	Jun. 30, 2013 Interest Expense	Jun. 30, 2012 Interest Expense	Jun. 30, 2013 Interest Expense	Jun. 30, 2012 Interest Expense	Jun. 30, 2013 Other current liabilities	Dec. 31, 2012 Other non-current liabilities
Derivative
Interest Rate Derivative Instruments Not Designated as Hedging Instruments, Liability at Fair Value													$ 34	$ 56
Interest rate swaps, number of instruments					2	2
Interest rate swaps, notional amount					1,000	1,000	500	500
Basis of interest payment					three month LIBOR	three month LIBOR	three month LIBOR	three month LIBOR
Fixed interest rate paid under agreement (as a percent)							4.93%	4.92%
Cash flow hedging contracts, net gains (losses) recognized in Accumulated Other Comprehensive Income (Loss)	0	9	0	16
Cash flow hedging contracts, amount of gains (losses) reclassified from Accumulated Other Comprehensive Income (Loss) to Interest Expense									0	(11)	0	(22)
Loss on interest rate derivative instruments not designated as hedging instruments recognized in Other, net in the Consolidated Statement of Operations	$ (1)		$ (1)