Stock-Based Compensation - Stock Based Compensation Expense Allocation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock based compensation expense	$ 11,912	$ 15,684	$ 25,549
Stock based compensation from continuing operations	11,450	14,614	24,345
Stock based compensation from discontinued operations	462	1,070	1,204
Employee Stock Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock based compensation expense	10,862	14,652	23,881
Non Employee Stock Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock based compensation expense	1,050	1,032	1,668
Research and Development Expense [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock based compensation from continuing operations	2,623	4,562	7,407
Selling, General and Administrative Expenses [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock based compensation from continuing operations	$ 8,827	$ 10,052	$ 16,938