Subsequent Events (Details) (USD $)	3 Months Ended		0 Months Ended			0 Months Ended					0 Months Ended
	Mar. 31, 2014	Mar. 31, 2014 Credit Facility	Nov. 25, 2013 7.25% senior notes due 2019	Mar. 31, 2014 7.25% senior notes due 2019	Dec. 31, 2013 7.25% senior notes due 2019	Apr. 01, 2014 Subsequent event Restricted stock units	Apr. 01, 2014 Subsequent event Restricted stock units Minimum	Apr. 01, 2014 Subsequent event Restricted stock units Maximum	May 02, 2014 Subsequent event Credit Facility	May 06, 2014 Subsequent event 5% senior subordinated notes	Apr. 23, 2014 Subsequent event 7.25% senior notes due 2019
Subsequent events
Granted (in shares)						1,902,889
Weighted average grant date fair value						$ 123,800,000
Weighted average period for recognizing unrecognized stock-based compensation expense	3 years						3 years 6 months	4 years
Percentage of the principal amount of the debt instrument which the entity may redeem with the proceeds from initial public offering			100.00%								100.00%
Face amount of the Credit Facility before amendment									2,500,000,000
Face amount of the Credit Facility		2,500,000,000							3,500,000,000
Borrowing base before amendment									2,000,000,000
Borrowing base		2,000,000,000							3,000,000,000
Lender commitments before amendment									1,500,000,000
Lender commitments		1,500,000,000							2,000,000,000
Senior notes issued										$ 600,000,000
Interest rate (as a percent)				7.25%	7.25%					5.125%