Goodwill and Other Intangible Assets - Gross Carrying Amounts and Accumulated Amortization Relating to Other Intangible Assets (Detail) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 1,924,410	$ 1,716,479
Accumulated Amortization	(355,484)	(304,837)
Net	1,568,926	1,411,642	$ 1,400,392
Customer relationships
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	1,556,579	1,356,353
Accumulated Amortization	(310,043)	(267,818)
Net	1,246,536	1,088,535
Trademarks
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	362,543	355,117
Accumulated Amortization	(40,504)	(32,755)
Net	322,039	322,362
Non-competition agreements
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	5,288	5,009
Accumulated Amortization	(4,937)	(4,264)
Net	$ 351	$ 745