Goodwill and Other Intangible Assets - Gross Carrying Amounts and Accumulated Amortization Relating to Other Intangible Assets (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 1,716,479	$ 1,628,241
Accumulated Amortization	(304,837)	(227,849)
Net	1,411,642	1,400,392	$ 618,510
Customer Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	1,356,353	1,251,783
Accumulated Amortization	(267,818)	(199,741)
Net	1,088,535	1,052,042
Trademarks [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	355,117	369,512
Accumulated Amortization	(32,755)	(23,056)
Net	322,362	346,456
Noncompete Agreements [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	5,009	6,946
Accumulated Amortization	(4,264)	(5,052)
Net	$ 745	$ 1,894