Debt (Details 2) (USD $)	12 Months Ended					0 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2013 Debt discount	Dec. 31, 2013 Deferred financing costs	Feb. 11, 2014 Term Loan	Dec. 31, 2013 Term Loan	Oct. 11, 2013 Term Loan	Dec. 31, 2013 Revolver	Oct. 11, 2013 Revolver	Dec. 31, 2013 Unsecured Notes	Dec. 31, 2013 2021 Notes	Sep. 19, 2013 2021 Notes	Dec. 31, 2013 2021 Notes Fair value measurements using significant other observable inputs (Level 2)	Dec. 31, 2013 2023 Notes	Sep. 19, 2013 2023 Notes	Dec. 31, 2013 2023 Notes Fair value measurements using significant other observable inputs (Level 2)
Long-term Debt
Gross Carrying Amount	$ 4,744,000,000						$ 2,494,000,000					$ 1,500,000,000	$ 1,500,000,000		$ 750,000,000	$ 750,000,000
Unamortized Discount	(51,000,000)						(12,000,000)					(26,000,000)			(13,000,000)
Net Carrying Amount	4,693,000,000						2,482,000,000					1,474,000,000			737,000,000
Less: current portion of long-term debt	(25,000,000)	0
Total Gross Carrying Amount, Long-term debt	4,719,000,000
Total Net Carrying Amount, Long-Term Debt	4,668,000,000	0
Maturites of Debt
2014	25,000,000
2015	25,000,000
2016	25,000,000
2017	25,000,000
2018	25,000,000
Thereafter	4,619,000,000
Total	4,744,000,000						2,494,000,000					1,500,000,000	1,500,000,000		750,000,000	750,000,000
Interest payable											38,000,000
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
Interest rate													5.625%			6.125%
Fees and financing costs	59,000,000	0	0	52,000,000	7,000,000
Fair Value of Notes														1,559,000,000			785,000,000
Percentage of principal repayable to option holders upon certain criteria	101.00%
Maximum percentage of outstanding Notes that can be redeemed with net cash proceeds from one or more qualified equity offerings	35.00%
Amortization of the debt discount	1,000,000
Percentage of Revolver outstanding which triggers certain financial covenants									15.00%
Repayment of long-term debt	(6,000,000)	0	0			(375,000,000)
Reduction of contractual principal repayments in 2014						25,000,000
Reduction of contractual principal repayments in 2015						25,000,000
Reduction of contractual principal repayments in 2016						25,000,000
Reduction of contractual principal repayments in 2017						25,000,000
Reduction of contractual principal repayments in 2018						25,000,000
Reduction of contractual principal repayments in 2019 through maturity						$ 250,000,000