Stock Based Compensation - Schedule of Stock-Based Compensation Cost (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense recognized	$ 6,676	$ 3,133	$ 8,820	$ 6,043
Stock Options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense recognized	1,736	2,013	3,340	3,877
Vesting of Restricted Stock Grants
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense recognized	540	1,120	1,080	2,166
Stock Awarded to Directors and Officers
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense recognized	4,400		4,400
Cost of Product Sales
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense recognized	26		48
Research and Development Expenses
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense recognized	447	1,610	908	3,165
Selling, General, and Administrative
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense recognized	$ 6,203	$ 1,523	$ 7,864	$ 2,878