Goodwill and Other Intangible Assets - Summary of Allocation of Acquisition Intangible Assets (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Acquired Finite Lived Intangible Assets [Line Items]
Goodwill	$ 840,117	$ 753,718	$ 657,987
Amortizable intangibles, Gross carrying amount	616,051	461,234
Amortizable intangibles, Accumulated Amortization	237,137	184,382
Customer related intangibles
Acquired Finite Lived Intangible Assets [Line Items]
Amortizable intangibles, Gross carrying amount	$ 321,019	$ 238,219
Amortizable intangibles, Weighted Average Amortization Period	16 years	15 years
Amortizable intangibles, Accumulated Amortization	$ 97,320	$ 78,120
Acquired software
Acquired Finite Lived Intangible Assets [Line Items]
Amortizable intangibles, Gross carrying amount	$ 262,286	$ 202,416
Amortizable intangibles, Weighted Average Amortization Period	7 years	7 years
Amortizable intangibles, Accumulated Amortization	$ 130,416	$ 99,772
Trade names
Acquired Finite Lived Intangible Assets [Line Items]
Amortizable intangibles, Gross carrying amount	$ 22,905	$ 16,905
Amortizable intangibles, Weighted Average Amortization Period	11 years	11 years
Amortizable intangibles, Accumulated Amortization	$ 7,205	$ 5,139
Capitalized software development costs
Acquired Finite Lived Intangible Assets [Line Items]
Amortizable intangibles, Gross carrying amount	$ 4,804	0
Amortizable intangibles, Weighted Average Amortization Period	5 years
Amortizable intangibles, Accumulated Amortization	$ 296	0
Leases acquired
Acquired Finite Lived Intangible Assets [Line Items]
Amortizable intangibles, Gross carrying amount	$ 5,037	$ 3,694
Amortizable intangibles, Weighted Average Amortization Period	9 years	10 years
Amortizable intangibles, Accumulated Amortization	$ 1,900	$ 1,351