Goodwill and Identifiable Intangible Assets - Information on Identifiable Intangible Assets (Detail) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2016	Dec. 31, 2015
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 583,130	$ 583,130
Accumulated Amortization	174,738	146,503
Net Carrying Amount	$ 408,392	436,627
Customer contractual relationships
Finite-Lived Intangible Assets [Line Items]
Weighted Average Amortization Period	17 years
Gross Carrying Amount	$ 554,330	554,330
Accumulated Amortization	152,199	127,264
Net Carrying Amount	$ 402,131	427,066
Contractual Backlog
Finite-Lived Intangible Assets [Line Items]
Weighted Average Amortization Period	1 year
Gross Carrying Amount	$ 21,800	21,800
Accumulated Amortization	$ 21,800	18,850
Net Carrying Amount		2,950
Technology
Finite-Lived Intangible Assets [Line Items]
Weighted Average Amortization Period	15 years
Gross Carrying Amount	$ 7,000	7,000
Accumulated Amortization	739	389
Net Carrying Amount	$ 6,261	$ 6,611