Stock- Based Compensation Expense (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total Stock-Based Compensation Expense	$ 2,688	$ 2,791	$ 8,525	$ 7,894
Cost of Goods Sold
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total Stock-Based Compensation Expense	(155)	10	294	61
Selling, General and Administrative
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total Stock-Based Compensation Expense	2,226	2,195	6,719	5,669
Research and Development
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total Stock-Based Compensation Expense	$ 617	$ 586	$ 1,512	$ 2,164