Debt - Carrying Value of Debt (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Debt Instrument [Line Items]
Debt issuance costs	$ (9,372)	$ (14,424)
Total debt	743,918	924,159
Less current portion of term credit facility	95,293	95,293
Less current portion of debt issuance costs	(4,970)	(5,583)
Total long-term debt	653,595	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	365,290	460,583
Revolving Credit Facility
Debt Instrument [Line Items]
Total debt	$ 88,000	$ 178,000