Long-Term Debt and Other Financings - Interest Expense (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Interest expense
Interest expense	$ 172	$ 508	$ 461	$ 1,050
Silicon Valley Bank Loans
Interest expense
Interest expense	135	356	373	739
Novartis Note
Interest expense
Interest expense	$ 37	151	$ 88	309
Other
Interest expense
Interest expense		$ 1		$ 2