Debt - Carrying Value of Debt (Detail) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Debt Instrument [Line Items]
Debt issuance costs	$ (11,584)	$ (14,424)
Total debt	723,353	924,159
Less current portion of term credit facility	95,293	95,293
Less current portion of debt issuance costs	(5,095)	(5,583)
Total long-term debt	633,155	834,449
6.375% Senior Notes, due August 2020 [Member]
Debt Instrument [Line Items]
Total debt	300,000	300,000
Term Credit Facility [Member]
Debt Instrument [Line Items]
Total debt	412,937	460,583
Revolving Credit Facility
Debt Instrument [Line Items]
Total debt	$ 22,000	$ 178,000