Changes in Carrying Amount of Goodwill (Detail) $ in Thousands	6 Months Ended
	Jun. 30, 2017 USD ($)
Goodwill [Roll Forward]
Carrying amount of goodwill, December 31, 2016	$ 414,936
Currency translation adjustments	8,171
Carrying amount of goodwill, June 30, 2017	423,107
Domestic
Goodwill [Roll Forward]
Carrying amount of goodwill, December 31, 2016	180,006
Currency translation adjustments	0
Carrying amount of goodwill, June 30, 2017	180,006
International
Goodwill [Roll Forward]
Carrying amount of goodwill, December 31, 2016	19,391
Currency translation adjustments	6,676
Carrying amount of goodwill, June 30, 2017	26,067
Proprietary Products
Goodwill [Roll Forward]
Carrying amount of goodwill, December 31, 2016	215,539
Currency translation adjustments	1,495
Carrying amount of goodwill, June 30, 2017	$ 217,034