Debt - Summary of Debt (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Debt Instrument [Line Items]
Principal amount	$ 2,939,291
Debt issue costs, net	(31,764)	$ (28,367)
Debt	2,909,341	3,322,541
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Debt	290,000	1,100,000
Term Loans [Member]
Debt Instrument [Line Items]
Debt	263,101	263,400
Senior Unsecured Notes Due 2016 [Member]
Debt Instrument [Line Items]
Debt		125,000
6.875% Senior Unsecured Notes Due 2021 [Member]
Debt Instrument [Line Items]
Debt		450,000
6.375% Senior Unsecured Notes Due 2022 [Member]
Debt Instrument [Line Items]
Principal amount	350,000	350,000
Unamortized premium	1,814	2,168
Debt	351,814	352,168
5.750% Senior Unsecured Notes Due 2020 [Member]
Debt Instrument [Line Items]
Debt	210,340	217,240
4.000% Senior Unsecured Notes due 2022 [Member]
Debt Instrument [Line Items]
Debt	525,850	543,100
5.500% Senior Unsecured Notes Due 2024 [Member]
Debt Instrument [Line Items]
Debt	300,000	300,000
6.375% Senior Unsecured Notes due 2024 [Member]
Debt Instrument [Line Items]
Debt	500,000
5.250% Senior Unsecured Notes Due 2026 [Member]
Debt Instrument [Line Items]
Debt	500,000
Senior Unsecured Debt [Member]
Debt Instrument [Line Items]
Debt	$ 2,941,105	$ 3,350,908