Convertible Preferred Stock and Stockholders' Equity (Deficit) - Schedule of Convertible Preferred Stock (Details) - USD ($)	Dec. 31, 2020	Oct. 31, 2020	Jun. 30, 2020
Class Of Stock [Line Items]
Temporary Equity, Carrying value	$ 290,945,000
Temporary Equity, Liquidation Preference	$ 475,617,000
Common shares issuable upon conversion	37,419,080
Temporary Equity, preferred authorized	229,296,908	229,296,908	77,427,646
Temporary Equity, preferred shares issued	53,509,351
Temporary Equity, preferred shares outstanding	53,509,351
Series 1 Convertible Preferred Stock
Class Of Stock [Line Items]
Temporary Equity, preferred authorized	57,324,227
Series 2 Non-voting Convertible Preferred Stock
Class Of Stock [Line Items]
Temporary Equity, preferred authorized	57,324,227
Series C-1 Convertible Preferred Stock
Class Of Stock [Line Items]
Temporary Equity, Carrying value	$ 39,756,000
Temporary Equity, Liquidation Preference	$ 105,041,000
Common shares issuable upon conversion	9,373,556
Temporary Equity, preferred authorized	13,404,197	13,404,197	13,404,197
Temporary Equity, preferred shares issued	13,404,197
Temporary Equity, preferred shares outstanding	13,404,197
Series C-2 Convertible Preferred Stock
Class Of Stock [Line Items]
Temporary Equity, preferred authorized	13,404,197	13,404,197	13,404,197
Series D-1 Convertible Preferred Stock
Class Of Stock [Line Items]
Temporary Equity, Carrying value	$ 3,561,000
Temporary Equity, Liquidation Preference	$ 5,631,000
Common shares issuable upon conversion	1,005,013
Temporary Equity, preferred authorized	11,809,630	11,809,630	11,809,626
Temporary Equity, preferred shares issued	1,437,178
Temporary Equity, preferred shares outstanding	1,437,178
Series D-2 Convertible Preferred Stock
Class Of Stock [Line Items]
Temporary Equity, Carrying value	$ 24,365,000
Temporary Equity, Liquidation Preference	$ 40,641,000
Common shares issuable upon conversion	7,253,461
Temporary Equity, preferred authorized	11,809,630	11,809,630	11,809,626
Temporary Equity, preferred shares issued	10,372,452
Temporary Equity, preferred shares outstanding	10,372,452
Series E-1 Convertible Preferred Stock
Class Of Stock [Line Items]
Temporary Equity, Carrying value	$ 16,943,000
Temporary Equity, Liquidation Preference	$ 24,319,000
Common shares issuable upon conversion	1,601,316
Temporary Equity, preferred authorized	13,477,088	13,477,088	13,500,000
Temporary Equity, preferred shares issued	2,289,899
Temporary Equity, preferred shares outstanding	2,289,899
Series E-2 Convertible Preferred Stock
Class Of Stock [Line Items]
Temporary Equity, Carrying value	$ 82,766,000
Temporary Equity, Liquidation Preference	$ 118,808,000
Common shares issuable upon conversion	7,823,208
Temporary Equity, preferred authorized	13,477,088	13,477,088	13,500,000
Temporary Equity, preferred shares issued	11,187,189
Temporary Equity, preferred shares outstanding	11,187,189
Series F-1 Convertible Preferred Stock
Class Of Stock [Line Items]
Temporary Equity, Carrying value	$ 38,496,000
Temporary Equity, Liquidation Preference	$ 59,420,000
Common shares issuable upon conversion	3,398,514
Temporary Equity, preferred authorized	18,633,312
Temporary Equity, preferred shares issued	4,859,897
Temporary Equity, preferred shares outstanding	4,859,897
Series F-2 convertible preferred stock
Class Of Stock [Line Items]
Temporary Equity, Carrying value	$ 85,058,000
Temporary Equity, Liquidation Preference	$ 121,757,000
Common shares issuable upon conversion	6,964,012
Temporary Equity, preferred authorized	18,633,312
Temporary Equity, preferred shares issued	9,958,539
Temporary Equity, preferred shares outstanding	9,958,539