Debt - Summary of Debt and Capital Lease Obligations (Detail) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Total Debt	$ 1,536,812	$ 1,502,554
Less amounts due within one year	(20)	(20)
Total long-term debt	1,536,792	1,502,534
$400 Million Term Loan B [Member]
Debt Instrument [Line Items]
Total Debt	384,035	384,727
$350 Million 5% Senior Notes [Member]
Debt Instrument [Line Items]
Total Debt	345,980	345,754
$400 Million 5% Senior Notes [Member]
Debt Instrument [Line Items]
Total Debt	394,479	394,281
$700 Million Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Total Debt	411,664	377,133
Capital Lease Obligations [Member]
Debt Instrument [Line Items]
Total Debt	$ 654	$ 659