Intangible Assets, Net - Summary of Carrying Amount of Intangible Assets by Major Asset Class (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value as of Acquisition Date	$ 181,273	$ 181,273
Accumulated Amortization	(78,208)	(63,860)
Net Carrying Value	103,065	117,413	$ 131,883
Customer relationships
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value as of Acquisition Date	173,746	173,746
Accumulated Amortization	(74,250)	(60,603)
Net Carrying Value	$ 99,496	113,143
Customer relationships | Minimum
Finite-Lived Intangible Assets [Line Items]
Estimated  Useful Life in Years	12 years
Customer relationships | Maximum
Finite-Lived Intangible Assets [Line Items]
Estimated  Useful Life in Years	20 years
Trademark and trade name
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value as of Acquisition Date	$ 7,527	7,527
Accumulated Amortization	(3,958)	(3,257)
Net Carrying Value	$ 3,569	$ 4,270
Trademark and trade name | Minimum
Finite-Lived Intangible Assets [Line Items]
Estimated  Useful Life in Years	8 years
Trademark and trade name | Maximum
Finite-Lived Intangible Assets [Line Items]
Estimated  Useful Life in Years	15 years