Share-Based Compensation - Summary of Stock Option Activity (Details) - USD ($)	6 Months Ended		12 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020
Options Outstanding
Beginning balance (in shares)	25,087,416
Granted (in shares)	3,722,000
Exercised (in shares)	(5,249,500)
Expired (in shares)	(2,891,509)
Forfeited (in shares)	(2,957,750)
Ending balance (in shares)	17,710,657		25,087,416
Vested at end of period (in shares)	10,841,824
Expected to vest at end of period (in shares)	6,868,833
Weighted Average Exercise Price
Beginning balance (in dollars per share)	$ 1.29
Granted (in dollars per share)	2.76
Exercised (in dollars per share)	1.55
Expired (in dollars per share)	1.73
Forfeited (in dollars per share)	0.58
Ending balance (in dollars per share)	1.57		$ 1.29
Vested at end of period (in dollars per share)	1.43
Expected to vest at end of period (in dollars per share)	$ 1.79
Weighted Average Remaining Contractual Life (Years)
Outstanding	8 years 6 months 29 days		0 years
Vested at end of period (in years)	8 years 14 days
Expected to vest at end of period (in years)	9 years 5 months 8 days
Aggregate Intrinsic Value
Outstanding at beginning period	$ 0
Exercised	5,249,163	$ 59,847
Outstanding at end of period	23,635,755		$ 0
Vested at end of period	16,073,579
Expected to vest at end of period	$ 7,562,176