Debt (Details 2) (USD $)	3 Months Ended	6 Months Ended			0 Months Ended
	Jun. 30, 2014	Jun. 30, 2014	Jun. 30, 2013	Dec. 31, 2013	Feb. 11, 2014 Term Loan	Jun. 30, 2014 Term Loan	Dec. 31, 2013 Term Loan	Oct. 11, 2013 Term Loan	Jun. 30, 2014 Term Loan Fair value measurements using significant other observable inputs (Level 2)	Dec. 31, 2013 Term Loan Fair value measurements using significant other observable inputs (Level 2)	Jun. 30, 2014 Revolver	Oct. 11, 2013 Revolver	Jun. 30, 2014 Unsecured Notes	Dec. 31, 2013 Unsecured Notes	Jun. 30, 2014 2021 Notes	Dec. 31, 2013 2021 Notes	Sep. 19, 2013 2021 Notes	Jun. 30, 2014 2021 Notes Fair value measurements using significant other observable inputs (Level 2)	Dec. 31, 2013 2021 Notes Fair value measurements using significant other observable inputs (Level 2)	Jun. 30, 2014 2023 Notes	Dec. 31, 2013 2023 Notes	Sep. 19, 2013 2023 Notes	Jun. 30, 2014 2023 Notes Fair value measurements using significant other observable inputs (Level 2)	Dec. 31, 2013 2023 Notes Fair value measurements using significant other observable inputs (Level 2)
Long-term Debt
Total	$ 4,369,000,000	$ 4,369,000,000		$ 4,744,000,000		$ 2,119,000,000	$ 2,494,000,000								$ 1,500,000,000	$ 1,500,000,000	$ 1,500,000,000			$ 750,000,000	$ 750,000,000	$ 750,000,000
Unamortized Discount	(48,000,000)	(48,000,000)		(51,000,000)		(11,000,000)	(12,000,000)								(24,000,000)	(26,000,000)				(13,000,000)	(13,000,000)
Net Carrying Amount	4,321,000,000	4,321,000,000		4,693,000,000		2,108,000,000	2,482,000,000								1,476,000,000	1,474,000,000				737,000,000	737,000,000
Less: current portion of long-term debt	0	0		(25,000,000)
Total Gross Carrying Amount, Long-term debt	4,369,000,000	4,369,000,000		4,719,000,000
Total Net Carrying Amount, Long-Term Debt	4,321,000,000	4,321,000,000		4,668,000,000
Maturites of Debt
2014 (remaining six months)	0	0
2015	0	0
2016	0	0
2017	0	0
2018	0	0
Thereafter	4,369,000,000	4,369,000,000
Total	4,369,000,000	4,369,000,000		4,744,000,000		2,119,000,000	2,494,000,000								1,500,000,000	1,500,000,000	1,500,000,000			750,000,000	750,000,000	750,000,000
Interest payable													38,000,000	38,000,000
Deferred Financing Costs
Amortization Expense, Deferred Financing Costs	0	0
Financing Facilities
Maximum borrowing capacity								2,500,000,000				250,000,000
Maximum letter of credit that can be issued under the Revolver	50,000,000	50,000,000										50,000,000
Interest rate																	5.625%					6.125%
Fair Value of Notes									2,119,000,000	2,494,000,000								1,618,000,000	1,559,000,000				829,000,000	785,000,000
Percentage of principal repayable to option holders upon certain criteria	101.00%	101.00%
Maximum percentage of outstanding Notes that can be redeemed with net cash proceeds from one or more qualified equity offerings	35.00%	35.00%
Amortization of the debt discount	2,000,000	3,000,000
Commitment fees for the Revolver	0	0
Percentage of Revolver outstanding which triggers certain financial covenants											15.00%
Repayment of long-term debt		$ (375,000,000)	$ 0		$ (375,000,000)