Goodwill and Other Intangible Assets - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Jul. 27, 2017
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill deductible for income tax purposes	$ 988,000	$ 362,600
Impact of foreign exchange rates on intangible assets	24,200
Amortization expense of intangible assets	$ 211,849	$ 161,635	$ 159,740
NexTraq | Disposal Group, Held-for-sale or Disposed of by Sale, Not Discontinued Operations
Finite-Lived Intangible Assets [Line Items]
Disposal group, intangible assets				$ 41,800