Stock-Based Compensation (Employee Stock-Based Compensation Expense) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Employee Stock Based Compensation Expense
Stock-based compensation expense (in dollars)	$ 5,105	$ 4,542
Cost of product revenues
Employee Stock Based Compensation Expense
Stock-based compensation expense (in dollars)	191	176
Research and development
Employee Stock Based Compensation Expense
Stock-based compensation expense (in dollars)	1,389	1,237
Selling and marketing
Employee Stock Based Compensation Expense
Stock-based compensation expense (in dollars)	1,511	1,438
General and administrative
Employee Stock Based Compensation Expense
Stock-based compensation expense (in dollars)	$ 2,014	$ 1,691