Net Earnings Per Share - Potentially Dilutive Securities (Details) - shares	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total (in shares)	12,467,397	78,231,883	496,568,000	77,636,883,000
Redeemable convertible preferred stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total (in shares)		65,428,088		65,428,088,000
Options to purchase common stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total (in shares)	12,287,845	11,486,484	411,299,000	10,969,062,000
Employee stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total (in shares)	46,171
Restricted stock units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total (in shares)	133,381		85,269,000
Warrants to purchase common stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total (in shares)		103,652		100,268,000
Warrants to purchase convertible preferred stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total (in shares)		1,213,659		1,139,465,000