Debt - Summary of Debt and Capital Lease Obligations (Parenthetical) (Detail) - USD ($)	Dec. 31, 2016	Dec. 31, 2015
$400 Million Term Loan B [Member]
Debt Instrument [Line Items]
Total credit facility	$ 400,000,000
Unamortized deferred financing costs	5,273,000	$ 6,457,000
$350 Million 5% Senior Notes [Member]
Debt Instrument [Line Items]
Total Senior Notes	$ 350,000,000
Interest rate of Senior Notes	5.00%
Unamortized deferred financing costs	$ 4,246,000	5,107,000
$400 Million 5% Senior Notes [Member]
Debt Instrument [Line Items]
Total Senior Notes	$ 400,000,000
Interest rate of Senior Notes	5.00%
Unamortized deferred financing costs	$ 5,719,000	6,469,000
Credit Facility [Member]
Debt Instrument [Line Items]
Unamortized deferred financing costs	$ 5,267,000	$ 7,335,000