Goodwill and Intangibles - Intangible Assets and Accumulated Amortization Balances (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 164,645	$ 140,429
Accumulated Amortization	(83,282)	(69,727)
Net Carrying Amount	81,363	70,702
Customer relationships [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	134,918	115,285
Accumulated Amortization	(73,088)	(61,375)
Net Carrying Amount	61,830	53,910
Developed technology [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	8,762	8,854
Accumulated Amortization	(8,386)	(7,673)
Net Carrying Amount	376	1,181
Other [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	20,965	16,290
Accumulated Amortization	(1,808)	(679)
Net Carrying Amount	$ 19,157	$ 15,611