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Stock-based Compensation - Narrative (Details) - USD ($) $ / shares in Units, $ in Thousands	6 Months Ended	12 Months Ended		18 Months Ended
	Jun. 30, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Awards granted (in shares)		12,904,692	5,002,390
Compensation cost		$ 8,711	$ 2,702
Weighted-average grant date fair value (in dollars per share)		$ 0.98	$ 0.68
Fair value of options vested		$ 1,400	$ 200
Unrecognized stock-based compensation expense		$ 11,200		$ 11,200
2020 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares authorized for issuance (in shares)		36,588,278		36,588,278
Awards granted (in shares)		0
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation cost		$ 3,200	200
Unrecognized compensation expense, period for recognition		2 years 14 days
Stock Options \| 2015 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period (in years)		4 years
Award expiration period (in years)		10 years
Stock Options \| First Anniversary of Grant Date
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period (in years)		1 year
Stock Options \| First Anniversary of Grant Date \| 2015 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting percentage		25.00%
Stock Options \| Monthly Vesting \| 2015 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period (in years)		36 months
Award vesting percentage		75.00%
Restricted Stock \| Share-based Payment Arrangement, Employee
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period (in years)	4 years
Compensation cost		$ 2,400	$ 2,400
Unrecognized compensation expense, period for recognition		1 year 5 months 15 days
Granted (in shares)		0	2,055,545	0
Fair value of restricted stock vested		$ 2,200	$ 2,500
Unrecognized stock-based compensation expense for restricted stock		1,900		$ 1,900
Restricted Stock \| Share-based Payment Arrangement, Nonemployee
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation cost		$ 124	$ 44
Unrecognized compensation expense, period for recognition		1 year 3 months 14 days
Granted (in shares)		0	0
Restricted Stock \| First Anniversary of Grant Date \| Share-based Payment Arrangement, Employee
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period (in years)	1 year
Award vesting percentage	25.00%
Restricted Stock \| Monthly Vesting \| Share-based Payment Arrangement, Employee
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period (in years)	36 months
Award vesting percentage	75.00%