Goodwill and Other Intangible Assets - Schedule of Intangible Assets (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Finite-Lived Intangible Assets [Line Items]
Intangible assets, Gross Amount	$ 1,648,149	$ 1,638,944
Intangible assets, Accumulated Amortization	980,128	896,758
Customer Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Intangible assets, Gross Amount	1,421,962	1,412,954
Intangible assets, Accumulated Amortization	838,443	767,532
Trademarks and Trade Names [Member]
Finite-Lived Intangible Assets [Line Items]
Intangible assets, Gross Amount	162,365	162,183
Intangible assets, Accumulated Amortization	100,000	92,258
Other [Member]
Finite-Lived Intangible Assets [Line Items]
Intangible assets, Gross Amount	63,822	63,807
Intangible assets, Accumulated Amortization	$ 41,685	$ 36,968