Stock-based Compensation - Narrative (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2021 USD ($) segment $ / shares shares	Sep. 30, 2020 USD ($) $ / shares	Sep. 30, 2021 USD ($) segment $ / shares shares	Sep. 30, 2020 USD ($) $ / shares	Dec. 31, 2020 shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense | $	$ 1,347,000	$ 126,000	$ 4,275,000	$ 497,000
Unrecognized compensation expense | $	$ 13,900,000		$ 13,900,000
Number of equity compensation plans | segment	2		2
Options outstanding, beginning balance (in shares)	10,518,263		10,518,263		4,224,433
Options, grants in period, weighted average grant date fair value (in USD per share) | $ / shares	$ 5.97	$ 0.34	$ 2.77	$ 0.34
Options, vested in period, fair value | $	$ 100,000	$ 100,000	$ 700,000	$ 300,000
2014 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized for grant (in shares)	800,000		800,000
2019 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized for grant (in shares)	11,500,000		11,500,000
Options to purchase common stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation expense related to options outstanding, weighted average period for expense to be recognized			2 years 2 months 12 days
Share-based Payment Arrangement, Performance Based Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense | $	$ 41,300	$ 0	$ 1,100,000	$ 0
Options not yet exercisable (in shares)	1,500,000		1,500,000
Options outstanding, beginning balance (in shares)					0