Goodwill and Intangibles - Intangible Assets and Accumulated Amortization Balances (Detail) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 165,197	$ 164,645
Accumulated Amortization	(86,999)	(83,282)
Net Carrying Amount	78,198	81,363
Customer relationships [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	135,029	134,918
Accumulated Amortization	(76,374)	(73,088)
Net Carrying Amount	58,655	61,830
Developed technology [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	8,801	8,762
Accumulated Amortization	(8,568)	(8,386)
Net Carrying Amount	233	376
Other [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	21,367	20,965
Accumulated Amortization	(2,057)	(1,808)
Net Carrying Amount	$ 19,310	$ 19,157