Stock-Based Compensation (Employee Stock-Based Compensation Expense) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Employee Stock Based Compensation Expense
Stock-based compensation expense (in dollars)	$ 4,542	$ 4,176
Cost of product revenues
Employee Stock Based Compensation Expense
Stock-based compensation expense (in dollars)	160	135
Research and development expense.
Employee Stock Based Compensation Expense
Stock-based compensation expense (in dollars)	1,253	1,041
Selling and marketing
Employee Stock Based Compensation Expense
Stock-based compensation expense (in dollars)	1,438	1,081
General and administrative
Employee Stock Based Compensation Expense
Stock-based compensation expense (in dollars)	$ 1,691	$ 1,919