Summary of Product Revenue Allowances and Reserve Categories (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Valuation Allowance [Line Items]
Beginning balance	$ 2,527	$ 610
Provision	15,500	5,774
Payments or credits	(12,905)	(3,857)
Ending balance	5,122	2,527
Trade Allowances
Valuation Allowance [Line Items]
Beginning balance	72	18
Provision	1,204	723
Payments or credits	(1,165)	(669)
Ending balance	111	72
Rebates Chargebacks and Discounts
Valuation Allowance [Line Items]
Beginning balance	2,095	515
Provision	13,586	3,798
Payments or credits	(11,221)	(2,218)
Ending balance	4,460	2,095
Other Incentives/ Returns
Valuation Allowance [Line Items]
Beginning balance	360	77
Provision	710	1,253
Payments or credits	(519)	(970)
Ending balance	$ 551	$ 360