Derivative Financial Instruments (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		1 Months Ended	3 Months Ended	1 Months Ended		3 Months Ended				3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Mar. 31, 2007 Level 3 Financing Inc. derivatives	Mar. 31, 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	Mar. 31, 2013 Interest Expense	Mar. 31, 2012 Interest Expense	Mar. 31, 2013 Other current liabilities	Dec. 31, 2012 Other non-current liabilities	Mar. 31, 2013 less than
Derivative
Interest Rate Derivative Instruments Not Designated as Hedging Instruments, Liability at Fair Value									$ 45	$ 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, gains (losses) recognized in Other Comprehensive Income (Loss)	0	7
Cash flow hedging contracts, amount of gains (losses) reclassified from AOCI to Interest Expense							0	11
Loss on interest rate derivative instruments not designated as hedging instruments recognized in Other, net in the Consolidated Statement of Operations											$ 1