Subsequent Events (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended						0 Months Ended					0 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013 Tranche B-II 2019 Term Loan	Dec. 31, 2012 Tranche B-II 2019 Term Loan	Sep. 30, 2013 10% Senior Notes due 2018	Dec. 31, 2012 10% Senior Notes due 2018	Oct. 04, 2013 Level 3 Financing, Inc. Subsequent Event Tranche B-II 2019 Term Loan	Oct. 04, 2013 Level 3 Financing, Inc. Subsequent Event Tranche B 2020 Term Loan add-on	Oct. 04, 2013 Level 3 Financing, Inc. Subsequent Event Tranche B 2020 Term Loan new aggregate principal amount	Oct. 30, 2013 Level 3 Financing, Inc. Subsequent Event 6.125% Senior Notes due 2021	Oct. 30, 2013 Level 3 Financing, Inc. Subsequent Event 10% Senior Notes due 2018	Oct. 04, 2013 London Interbank Offered Rate (LIBOR) Level 3 Financing, Inc. Subsequent Event Tranche B-II 2019 Term Loan	Oct. 04, 2013 London Interbank Offered Rate (LIBOR) Level 3 Financing, Inc. Subsequent Event Tranche B 2020 Term Loan new aggregate principal amount	Oct. 04, 2013 London Interbank Offered Rate (LIBOR) Level 3 Financing, Inc. Minimum Subsequent Event Tranche B-II 2019 Term Loan	Oct. 04, 2013 London Interbank Offered Rate (LIBOR) Level 3 Financing, Inc. Minimum Subsequent Event Tranche B 2020 Term Loan new aggregate principal amount
Subsequent Event
Refinanced debt amount									$ 1,200.0
Aggregate principal amount										1,200.0	1,796.0	640.0
Basis (LIBOR)														LIBOR	LIBOR
Basis Spread on Variable Rate														3.25%	3.00%
Stated interest rate (as a percent)					4.75%	4.75%	10.00%	10.00%				6.125%	10.00%			1.50%	1.00%
Upfront fee at closing										0.25%
Loss on the refinancing	(17)	(49)	(17)	(110)					(10)
Additional debt discount costs										$ 3