Debt - Summary of Debt and Capital Lease Obligations (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Debt Instrument [Line Items]
Total Debt	$ 1,649,302	$ 1,591,392
$200 Million Term Loan A [Member]
Debt Instrument [Line Items]
Total Debt	198,526	198,443
$500 Million Term Loan B [Member]
Debt Instrument [Line Items]
Total Debt	488,920	488,655
$350 Million 5% Senior Notes [Member]
Debt Instrument [Line Items]
Total Debt	346,899	346,660
$400 Million 5% Senior Notes [Member]
Debt Instrument [Line Items]
Total Debt	395,279	395,071
$700 Million Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Total Debt	219,044	161,924
Capital Lease Obligations [Member]
Debt Instrument [Line Items]
Total Debt	$ 634	$ 639