Warrant Options - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Millions			12 Months Ended
	Jul. 30, 2020	Jul. 27, 2020	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Jul. 29, 2020	Apr. 30, 2020	Apr. 13, 2020	Oct. 19, 2018
Class Of Warrant Or Right [Line Items]
Period between issuance and expiration of outstanding warrant								10 years
Exercise of redeemable A1 preferred stock warrant shares			2,534,239
Share price			$ 21.81	$ 26.97	$ 20.65
Increase of shares					674,008
Common Stock
Class Of Warrant Or Right [Line Items]
Warrant exercise price per share	$ 0.01
Increase of shares					674,008
Exercise of Redeemable Convertible A2 Preferred Stock Warrant Shares	1,999,999
Exercise of Redeemable Convertible A2 Preferred Stock Warrant Value	$ 44.4
Redeemable Series A-1 Preferred Stock
Class Of Warrant Or Right [Line Items]
Warrants to purchase common stock									534,240
Warrant exercise price per share									$ 0.01
Period between issuance and expiration of outstanding warrant									10 years
Fair value of warrants			$ 16.9			$ 11.9
Warrants exercised in full for cash, date			Jul. 30, 2020
Redeemable Series A-1 Preferred Stock | Other Expense
Class Of Warrant Or Right [Line Items]
Fair value gains/(losses) of warrants			$ 9.3	$ 4.1	$ 0.0
Redeemable Series A-1 Preferred Stock | Common Stock
Class Of Warrant Or Right [Line Items]
Warrant exercise price per share	$ 0.01
Exercise of redeemable A1 preferred stock warrant shares	534,240
Redeemable Series A-2 Preferred Stock
Class Of Warrant Or Right [Line Items]
Warrants to purchase common stock							1,351,960
Warrant exercise price per share							$ 0.01
Period between issuance and expiration of outstanding warrant							10 years
Aggregate value to determine number of shares underlying the warrant and issuable upon exercise of warrants							$ 30.0
Convertible And Redeemable Series A-2 Preferred Stock
Class Of Warrant Or Right [Line Items]
Warrants to purchase common stock		1,999,999
Share price		$ 15.00
Increase of shares		648,039