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, 2021	Dec. 31, 2020
Liabilities:
Long-term obligations	$ 2,184,400	$ 2,280,353
Quoted Prices in Active Markets for Identical Assets and Liabilities (Level 1)
Liabilities:
Long-term obligations	984,400	787,975
Significant Other Observable Inputs (Level 2) [Member]
Liabilities:
Long-term obligations	$ 1,200,000	$ 1,492,378