Commitments and Contingencies - Future Minimum Lease Payments and Long-Term Debt Maturities (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Minimum Lease Payments
2021	$ 604	$ 2,179
2022	2,445	2,445
2023	2,092	2,092
2024	0	0
Total minimum payments	5,141	6,716
Less: amount representing interest/unamortized debt discount	(559)	(912)
Present value of future payments	4,582	5,804
Less: current portion	(2,032)	(1,708)
Non-current portion	2,550	4,096
Debt Repayments
2021	0	0
2022	0	6,250
2023	12,500	25,000
2024	37,500	18,750
Total minimum payments	50,000	50,000
Less: amount representing interest/unamortized debt discount	(238)	(1,042)
Present value of future payments	49,762	48,958
Less: current portion	0	(4,551)
Non-current portion	49,762	44,407
Total
2021	604	2,179
2022	2,445	8,695
2023	14,592	27,092
2024	37,500	18,750
Total minimum payments	55,141	56,716
Less: amount representing interest/unamortized debt discount	(797)	(1,954)
Present value of future payments	54,344	54,762
Less: current portion	(2,032)	(6,259)
Non-current portion	$ 52,312	$ 48,503

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