Stock Incentive Plans (Details) - Stock options - USD ($)	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020
Shares
Outstanding, beginning of period (in shares)			1,367,667
Granted (in shares)			6,447,000
Assumed in Quellis Acquisition (in shares)			332,494
Cancelled or forfeited (in shares)			(208,152)
Expired (in shares)			(8,675)
Outstanding, end of period (in shares)	7,930,334		7,930,334		1,367,667
Vested and exercisable (in shares)	770,141		770,141
Weighted-Average Exercise Price
Outstanding, beginning of period (in dollars per share)			$ 11.38
Granted (in dollars per share)			2.74
Assumed in Quellis Acquisition (in dollars per share)			0.29
Cancelled or forfeited (in dollars per share)			8.71
Expired (in dollars per share)			16.70
Outstanding at end of year (in dollars per share)	$ 3.96		3.96		$ 11.38
Vested and Exercisable (in dollars per share)	$ 14.07		$ 14.07
Weighted Average Remaining Contractual Term (years)
Outstanding			9 years 5 months 8 days		8 years 1 month 17 days
Vested and Exercisable			7 years 3 months 21 days
Aggregate Intrinsic Value
Outstanding	$ 662,000		$ 662,000
Vested and Exercisable	$ 207,000		$ 207,000
Stock Incentive Plans
Exercised (in shares)	0	0	0	0
Aggregate fair value of options vested	$ 400,000	$ 0.3	$ 1,000,000.0	$ 800,000
Weighted average grant date fair value of options granted (in dollars per share)	$ 1.73	$ 4.00	$ 1.73	$ 3.64
Unrecognized compensation expense related to unvested stock option awards	$ 12,700,000		$ 12,700,000
Weighted-average amortization period over which cost is expected to be recognized			3 years 3 months 18 days