Leases - Narrative (Details) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2021 USD ($)	Sep. 30, 2021 USD ($)	Feb. 01, 2021 EUR (€)
Operating Leased Assets [Line Items]
Operating lease, expense | $	$ 0.3	$ 0.8
Operating lease, rent expense | $	$ 0.2	$ 0.6
Operating lease, weighted average remaining lease term	3 years 6 months 21 days	3 years 6 months 21 days
Operating lease, weighted average discount rate, percent	8.00%	8.00%
Rantigen, Germany, Administrative Office One
Operating Leased Assets [Line Items]
Operating lease, monthly payments | €			€ 2,510
Rantigen, Germany, Administrative Office Two
Operating Leased Assets [Line Items]
Operating lease, monthly payments | €			€ 1,010