Goodwill and Other Intangible Assets - Other Intangible Assets (Detail) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Acquired Finite-Lived Intangible Assets [Line Items]
Gross amount	$ 701,091		$ 699,667
Accumulated amortization	(471,304)		(457,730)
Net carrying amount	229,787		241,937
Customer relationships
Acquired Finite-Lived Intangible Assets [Line Items]
Gross amount	343,557		344,883
Accumulated amortization	(226,905)		(220,434)
Net carrying amount	$ 116,652		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	$ 41,874		42,025
Accumulated amortization	(33,360)		(32,456)
Net carrying amount	$ 8,514		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	$ 259,121		256,220
Accumulated amortization	(175,230)		(169,974)
Net carrying amount	$ 83,891		$ 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	(35,809)		(34,866)
Net carrying amount	$ 20,730		$ 21,673