Balance Sheet Account Details (Accrued Expenses) (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Accrued interest expense	$ 2,692	$ 2,260
Accrued clinical trials	3,496	2,430
Accrued manufacturing costs	1,339	1,823
Accrued other	1,785	1,972
Total accrued expenses	$ 9,312	$ 8,485