Accrued Liabilities (Narrative) (Detail) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Sales Allowances and Accruals [Abstract]
Discount and Distribution Fees	$ 3,567	$ 2,475
Government rebates and chargebacks	11,149	5,514
Assistance and Other Discounts	3,282	2,580
Product return	2,654	1,769
Accrued liabilities, amounts received in advance of revenue recognition	$ 20,652	$ 12,338