Goodwill and Other Intangible Assets - Other Intangible Assets (Detail) - USD ($) $ in Thousands	6 Months Ended		12 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Acquired Finite-Lived Intangible Assets [Line Items]
Gross amount	$ 709,418		$ 699,667
Accumulated amortization	(484,813)		(457,730)
Net carrying amount	224,605		241,937
Customer relationships
Acquired Finite-Lived Intangible Assets [Line Items]
Gross amount	343,756		344,883
Accumulated amortization	(233,324)		(220,434)
Net carrying amount	$ 110,432		124,449
Customer relationships | Minimum
Acquired Finite-Lived Intangible Assets [Line Items]
Useful life in years	8 years	8 years
Customer relationships | Maximum
Acquired Finite-Lived Intangible Assets [Line Items]
Useful life in years	14 years	14 years
Trademarks
Acquired Finite-Lived Intangible Assets [Line Items]
Gross amount	$ 41,919		42,025
Accumulated amortization	(34,262)		(32,456)
Net carrying amount	$ 7,657		9,569
Trademarks | Minimum
Acquired Finite-Lived Intangible Assets [Line Items]
Useful life in years	10 years	2 years
Trademarks | Maximum
Acquired Finite-Lived Intangible Assets [Line Items]
Useful life in years	15 years	15 years
Software packages
Acquired Finite-Lived Intangible Assets [Line Items]
Gross amount	$ 267,204		256,220
Accumulated amortization	(180,477)		(169,974)
Net carrying amount	$ 86,727		$ 86,246
Software packages | Minimum
Acquired Finite-Lived Intangible Assets [Line Items]
Useful life in years	3 years	3 years
Software packages | Maximum
Acquired Finite-Lived Intangible Assets [Line Items]
Useful life in years	10 years	10 years
Non-compete agreement
Acquired Finite-Lived Intangible Assets [Line Items]
Useful life in years	15 years		15 years
Gross amount	$ 56,539		$ 56,539
Accumulated amortization	(36,750)		(34,866)
Net carrying amount	$ 19,789		$ 21,673