Intangible Assets and Goodwill - Additional Information (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2017 USD ($)
Finite Lived Intangible Assets [Line Items]
Product acquisition and licensing agreements obligation, Other Liability	$ 11,667
Product Registrations
Finite Lived Intangible Assets [Line Items]
Expected useful life	25 years
Trademarks
Finite Lived Intangible Assets [Line Items]
Expected useful life	25 years
Customer Lists
Finite Lived Intangible Assets [Line Items]
Expected useful life	10 years