Accrued Liabilities (Narrative) (Detail) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Sales Allowances and Accruals [Abstract]
Discount and Distribution Fees	$ 2,814	$ 2,475
Government rebates and chargebacks	6,960	5,514
Assistance and Other Discounts	4,288	2,580
Product return	3,004	1,769
Accrued liabilities, amounts received in advance of revenue recognition	$ 17,066	$ 12,338