Debt - Summary of Debt and Capital Lease Obligations (Parenthetical) (Detail) - USD ($)	9 Months Ended
	Sep. 30, 2017	Dec. 31, 2016
$200 Million Term Loan A [Member]
Debt Instrument [Line Items]
Total credit facility	$ 200,000,000
Unamortized deferred financing costs	$ 1,641,000	$ 0
Maturity date for credit facility	May 23, 2022
Spread rate added to LIBOR	1.50%
$500 Million Term Loan B [Member]
Debt Instrument [Line Items]
Total credit facility	$ 500,000,000
Unamortized deferred financing costs	$ 7,860,000	0
Maturity date for credit facility	May 11, 2024
Spread rate added to LIBOR	2.25%
$400 Million Term Loan B [Member]
Debt Instrument [Line Items]
Total credit facility	$ 400,000,000
Unamortized deferred financing costs	$ 0	5,273,000
Maturity date for credit facility	Jan. 15, 2021
Spread rate added to LIBOR	2.75%
$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	$ 3,566,000	4,246,000
Maturity date for Senior Notes	Apr. 15, 2021
$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	$ 5,126,000	5,719,000
Maturity date for Senior Notes	Apr. 15, 2023
$700 Million Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Total credit facility	$ 700,000,000
Unamortized deferred financing costs	$ 9,696,000	$ 5,267,000
Maturity date for credit facility	May 23, 2021
Spread rate added to LIBOR	1.55%