Financial Information for Subsidiary Guarantors and Non-Guarantors - Debt Instrument Information (Details)	9 Months Ended
	Sep. 30, 2017	Aug. 31, 2015
Debt Instrument
Interest rate, stated percentage	3.125%
Ownership percentage in Guarantor Subsidiaries	100.00%
Senior Notes 5.875%, due 2023
Debt Instrument
Interest rate, stated percentage	5.875%	5.875%
Senior Notes 5.375%, due 2025
Debt Instrument
Interest rate, stated percentage	5.375%
Senior Notes 6.375%, due 2025
Debt Instrument
Interest rate, stated percentage	6.375%