Goodwill and Intangibles - Intangible Assets and Accumulated Amortization Balances (Detail) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 202,577	$ 202,687
Accumulated Amortization	(111,950)	(103,085)
Net Carrying Amount	90,627	99,602
Customer relationships
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	156,732	157,286
Accumulated Amortization	(106,407)	(98,937)
Net Carrying Amount	50,325	58,349
Other
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	45,845	45,401
Accumulated Amortization	(5,543)	(4,148)
Net Carrying Amount	$ 40,302	$ 41,253