Fair Value of Financial Instruments - Liabilities, Non Recurring (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended			12 Months Ended			12 Months Ended			11 Months Ended		24 Months Ended		65 Months Ended						12 Months Ended
	Oct. 04, 2013 Tranche B-II 2019 Term Loan	Dec. 31, 2013 Tranche B-II 2019 Term Loan	Dec. 31, 2012 Tranche B-II 2019 Term Loan	Aug. 01, 2013 Tranche B 2019 Term Loan	Dec. 31, 2013 Tranche B 2019 Term Loan	Dec. 31, 2012 Tranche B 2019 Term Loan	Aug. 01, 2013 Tranche B 2016 Term Loan	Dec. 31, 2013 Tranche B 2016 Term Loan	Dec. 31, 2012 Tranche B 2016 Term Loan	Sep. 30, 2012 Tranche B III Term Loan	Dec. 31, 2011 Tranche B III Term Loan	Oct. 04, 2013 Tranche B II Term Loan	Dec. 31, 2011 Tranche B II Term Loan	Jul. 31, 2012 Tranche A Term Loan	Dec. 31, 2013 Senior Notes due 2019 (11.875%)	Dec. 31, 2011 Senior Notes due 2019 (11.875%)	Dec. 31, 2013 Senior Notes due 2019 (8.875%)	Dec. 31, 2013 Convertible Senior Notes due 2016 (6.5%)	Dec. 31, 2011 Convertible Senior Notes due 2016 (6.5%)	Dec. 31, 2013 Not actively traded convertible notes	Dec. 31, 2013 Convertible Senior Notes due 2015 (7.0%)	Dec. 31, 2011 Convertible Senior Notes due 2015 (7.0%)	Dec. 31, 2013 Convertible Senior Notes due 2015 Series B (7.0%)	Dec. 31, 2011 Convertible Senior Notes due 2015 Series B (7.0%)	Dec. 31, 2013 Convertible Senior Notes due 2013 (15.0%)	Mar. 31, 2012 Convertible Senior Notes due 2013 (15.0%)	Dec. 31, 2011 Convertible Senior Notes due 2013 (15.0%)	Dec. 31, 2013 Estimate of Fair Value, Fair Value Disclosure Term Loans	Dec. 31, 2012 Estimate of Fair Value, Fair Value Disclosure Actively traded convertible notes	Dec. 31, 2013 Estimate of Fair Value, Fair Value Disclosure Not actively traded convertible notes	Dec. 31, 2012 Estimate of Fair Value, Fair Value Disclosure Not actively traded convertible notes	Dec. 31, 2013 Fair Value, Measurements, Recurring Estimate of Fair Value, Fair Value Disclosure Senior Notes
Liabilities measured on a recurring basis
Term Loans																												$ 2,600
Debt instrument, Interest spread on debt (as percent)	3.25%			3.75%			3.25%			4.25%		4.25%		2.25%
Debt instrument, basis floor (as percent)		1.50%			1.50%			1.50%			1.50%		1.50%
Senior Notes																																5,700
Convertible Notes																													286	647	748
Debt instrument, stated interest rate (as a percent)			4.75%			5.25%			4.75%						11.875%	11.875%	8.875%	6.50%	6.50%		7.00%	7.00%	7.00%	7.00%	15.00%	15.00%	15.00%
Security coupon rates used for valuation, lowest interest rate																				7.00%
Security coupon rates used for valuation, highest interest rate																				15.00%
Carrying value of long term debt			$ 1,200						$ 599