Goodwill and Intangible Assets - Components of Intangible Assets (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Dec. 31, 2018
Acquired Finite Lived Intangible Assets [Line Items]
Finite lived intangible assets, Cost	$ 139,784	$ 139,784
Finite lived intangible assets, Accumulated amortization	(56,755)	(53,520)
Finite lived intangible assets, Net	83,029	86,264
Customer Lists [Member]
Acquired Finite Lived Intangible Assets [Line Items]
Finite lived intangible assets, Cost	113,357	113,357
Finite lived intangible assets, Accumulated amortization	(42,589)	(39,966)
Finite lived intangible assets, Net	$ 70,768	73,391
Customer Lists [Member] | Minimum [Member]
Acquired Finite Lived Intangible Assets [Line Items]
Useful life (years)	5 years
Customer Lists [Member] | Maximum [Member]
Acquired Finite Lived Intangible Assets [Line Items]
Useful life (years)	15 years
Patents and Technology [Member]
Acquired Finite Lived Intangible Assets [Line Items]
Finite lived intangible assets, Cost	$ 23,424	23,424
Finite lived intangible assets, Accumulated amortization	(11,163)	(10,551)
Finite lived intangible assets, Net	$ 12,261	12,873
Patents and Technology [Member] | Minimum [Member]
Acquired Finite Lived Intangible Assets [Line Items]
Useful life (years)	3 years
Patents and Technology [Member] | Maximum [Member]
Acquired Finite Lived Intangible Assets [Line Items]
Useful life (years)	10 years
Trade Names and Trademarks [Member]
Acquired Finite Lived Intangible Assets [Line Items]
Finite lived intangible assets, Cost	$ 3,003	3,003
Finite lived intangible assets, Accumulated amortization	$ (3,003)	$ (3,003)
Trade Names and Trademarks [Member] | Minimum [Member]
Acquired Finite Lived Intangible Assets [Line Items]
Useful life (years)	1 year
Trade Names and Trademarks [Member] | Maximum [Member]
Acquired Finite Lived Intangible Assets [Line Items]
Useful life (years)	2 years