Financial Instruments and Fair Value Measurements - Carrying Value and Estimated Fair Values (Detail) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Carrying Amount
Financial liabilities:
Interest rate swap	$ 28,123	$ 14,452
Carrying Amount | Credit Facility | 2023 Term A Loan
Financial liabilities:
Senior secured term loan	194,058	207,261
Carrying Amount | Credit Facility | 2024 Term B Loan
Financial liabilities:
Senior secured term loan	307,764	317,936
Fair Value
Financial liabilities:
Interest rate swap	28,123	14,452
Fair Value | Credit Facility | 2023 Term A Loan
Financial liabilities:
Senior secured term loan	187,439	206,388
Fair Value | Credit Facility | 2024 Term B Loan
Financial liabilities:
Senior secured term loan	$ 300,105	$ 324,163