Derivative Financial Instruments (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended			1 Months Ended			3 Months Ended		9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010	Mar. 31, 2007 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	Sep. 30, 2011 Interest Rate Swap	Sep. 30, 2011 Interest Expense	Sep. 30, 2010 Interest Expense	Sep. 30, 2011 Interest Expense	Sep. 30, 2010 Interest Expense	Sep. 30, 2011 Other Noncurrent Liabilities	Dec. 31, 2010 Other Noncurrent Liabilities	Sep. 30, 2011 Convertible Senior Notes due 2016 (6.5%)	Dec. 31, 2010 Convertible Senior Notes due 2016 (6.5%)	Sep. 30, 2010 Convertible Senior Notes due 2016 (6.5%)	Sep. 30, 2011 Convertible Senior Discount Notes due 2013 (9.0%)	Mar. 31, 2011 Convertible Senior Discount Notes due 2013 (9.0%)	Sep. 30, 2011 Convertible Senior Notes due 2011 (5.25%)	Mar. 31, 2011 Convertible Senior Notes due 2011 (5.25%)	Mar. 31, 2010 Convertible Senior Notes due 2011 (5.25%)	Sep. 30, 2011 Convertible Senior Notes due 2013 (15.0%)	Sep. 30, 2011 Cash Flow Hedging
Derivative [Line Items]
Debt Instrument, Face Amount																$ 26	$ 175
Interest rate of convertible senior notes (as a percent)															6.50%			9.00%	9.00%	5.25%	5.25%	5.25%	15.00%
Notional Amount of Interest Rate Cash Flow Hedge Derivatives	1,000		1,000		1,000	500	500
Basis of interest payment			LIBOR			three month LIBOR	three month LIBOR
Fixed interest rate paid under agreement (as a percent)						4.93%	4.92%
Embedded equity conversion rights located in Other Income (Expense) - Other, net	0	0	0	10
Interest Rate Derivatives
Interest rate swaps, Number of Instruments					2																			2
Fair value, Derivatives designated as hedging instruments
Cash flow hedging contracts													98	108
Amount of gains (losses) recognized in Other Comprehensive Loss, Derivatives designated as hedging instruments
Cash flow hedging contracts	2	(9)	10	(30)
Amount of gains (losses) reclassified from AOCI to Income/Loss (effective portions), Derivatives designated as hedging instruments
Cash flow hedging contracts - Interest Expense									(12)	(11)	(35)	(34)
Net losses on the interest rate swaps that will be reclassified into earnings during the next twelve months								$ 47