Intangible Assets, Net - Summary of Carrying Amount of Intangible Assets by Major Asset Class (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Finite-Lived Intangible Assets [Line Items]
Estimated Useful Life in Years	19 years
Gross Carrying Value as of Acquisition Date	$ 464,571	$ 301,230
Accumulated Amortization	(88,323)	(63,528)
Intangible assets, net	376,248	237,702	$ 254,263
Customer relationships
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value as of Acquisition Date	428,830	282,030
Accumulated Amortization	(75,581)	(52,408)
Intangible assets, net	353,249	229,622
Trademark and trade name
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value as of Acquisition Date	25,100	10,460
Accumulated Amortization	(4,085)	(2,703)
Intangible assets, net	21,015	7,757
Other
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value as of Acquisition Date	10,641	8,740
Accumulated Amortization	(8,657)	(8,417)
Intangible assets, net	$ 1,984	$ 323
Minimum | Customer relationships
Finite-Lived Intangible Assets [Line Items]
Estimated Useful Life in Years	12 years
Minimum | Trademark and trade name
Finite-Lived Intangible Assets [Line Items]
Estimated Useful Life in Years	8 years
Minimum | Other
Finite-Lived Intangible Assets [Line Items]
Estimated Useful Life in Years	1 year
Maximum | Customer relationships
Finite-Lived Intangible Assets [Line Items]
Estimated Useful Life in Years	20 years
Maximum | Trademark and trade name
Finite-Lived Intangible Assets [Line Items]
Estimated Useful Life in Years	30 years
Maximum | Other
Finite-Lived Intangible Assets [Line Items]
Estimated Useful Life in Years	5 years