Debt - Carrying Value of Debt (Detail) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Debt Instrument [Line Items]
Debt issuance costs	$ (12,846)	$ (14,424)
Total debt	758,914	924,159
Less current portion of term credit facility	95,293	95,293
Less current portion of debt issuance costs	(5,238)	(5,583)
Total long-term debt	668,859	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	436,760	460,583
Revolving Credit Facility
Debt Instrument [Line Items]
Total debt	$ 35,000	$ 178,000