Fair Value Measurements - Schedule of Assets and Liabilities Measured at Fair Value on a Recurring Basis (Detail) - Fair Value, Measurements, Recurring [Member] - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Liabilities:
Derivative financial instruments	$ 3,109
Long-term obligations	1,561,760	$ 1,553,389
Assets:
Derivative financial instruments		3,109
Significant Other Observable Inputs (Level 2) [Member]
Liabilities:
Derivative financial instruments	3,109
Long-term obligations	$ 1,561,760	1,553,389
Assets:
Derivative financial instruments		$ 3,109