Software and Other Intangible Assets - Carrying Amount and Accumulated Amortization of Other Intangible Assets (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 314,339	$ 321,864
Accumulated Amortization	(146,212)	(130,583)
Net Balance	168,127	191,281
Customer Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	297,991	305,218
Accumulated Amortization	(131,187)	(116,677)
Net Balance	166,804	188,541
Trademarks and Tradenames [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	16,348	16,646
Accumulated Amortization	(15,025)	(13,906)
Net Balance	$ 1,323	$ 2,740