Long-term Debt - Summary of Long-term Debt (Details) - Senior Notes [Member] - USD ($)		1 Months Ended
		Feb. 28, 2015	Sep. 30, 2015		Dec. 31, 2014
Debt Instrument [Line Items]
Net proceeds		$ 1,482,400,000
Debt issuance costs, net		$ 17,600,000
5.375% Senior Notes [Member]
Debt Instrument [Line Items]
Principal Amount at Par			$ 500,000,000		$ 500,000,000
Fair Value	[1]		$ 518,800,000		$ 520,000,000
Interest rate			5.375%		5.375%
5.750% Senior Notes [Member]
Debt Instrument [Line Items]
Principal Amount at Par			$ 400,000,000		$ 400,000,000
Fair Value	[1]		$ 408,000,000		$ 416,000,000
Interest rate			5.75%		5.75%
5.50% Senior Notes [Member]
Debt Instrument [Line Items]
Principal Amount at Par	[2]		$ 700,000,000
Fair Value	[1],[2]		$ 707,000,000		$ 0
Interest rate		5.50%	5.50%	[2]
5.875% Senior Notes [Member]
Debt Instrument [Line Items]
Principal Amount at Par	[2]		$ 800,000,000
Fair Value	[1],[2]		$ 822,000,000		$ 0
Interest rate		5.875%	5.875%	[2]

[1] Based on quoted market prices in less active markets

[2] The net proceeds to the Company for the 5.50% and 5.875% Senior Notes issued in the first quarter of 2015 were an aggregate $1,482.4 million. Debt issuance costs of $17.6 million were recorded in "Other non-current assets" on the Consolidated Balance Sheets and are amortized over the term of the notes as "Interest expense" on the Consolidated Statements of Operations.