Equity - Summary of Preferred Stock (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Jul. 14, 2020	Jun. 30, 2020	Dec. 31, 2019
Class Of Stock [Line Items]
Preferred Stock Authorized	0	46,809,523		33,085,827
Preferred Stock Issued	0	42,953,085		32,934,785
Preferred Stock Outstanding	0	42,953,085		32,934,785
Carrying Value		$ 326,313		$ 222,173
Liquidation Preference		$ 326,313		$ 222,173
Common Stock Issuable Upon Conversion		34,445,108		26,411,194
Series A Preferred Stock
Class Of Stock [Line Items]
Preferred Stock Authorized		9,696,798		9,696,798
Preferred Stock Issued		9,696,798		9,696,798
Preferred Stock Outstanding		9,696,798		9,696,798
Carrying Value		$ 31,063		$ 31,063
Liquidation Preference		$ 31,063		$ 31,063
Common Stock Issuable Upon Conversion		7,776,095		7,776,095
Series A-1 Preferred Stock
Class Of Stock [Line Items]
Preferred Stock Authorized		3,370,263		3,370,263
Preferred Stock Issued		3,253,645		3,253,645
Preferred Stock Outstanding		3,253,645		3,253,645
Carrying Value		$ 11,083		$ 11,083
Liquidation Preference		$ 11,083		$ 11,083
Common Stock Issuable Upon Conversion		2,609,176		2,609,176
Series B Preferred Stock
Class Of Stock [Line Items]
Preferred Stock Authorized		5,283,992		5,283,992
Preferred Stock Issued		5,249,568		5,249,568
Preferred Stock Outstanding		5,249,568		5,249,568
Carrying Value		$ 30,314		$ 30,314
Liquidation Preference		$ 30,314		$ 30,314
Common Stock Issuable Upon Conversion		4,209,754		4,209,754
Series C Preferred Stock
Class Of Stock [Line Items]
Preferred Stock Authorized		14,734,774		14,734,774
Preferred Stock Issued		14,734,774		14,734,774
Preferred Stock Outstanding		14,734,774		14,734,774
Carrying Value		$ 149,713		$ 149,713
Liquidation Preference		$ 149,713		$ 149,713
Common Stock Issuable Upon Conversion		11,816,169		11,816,169
Series D Preferred Stock
Class Of Stock [Line Items]
Preferred Stock Authorized		13,723,696
Preferred Stock Issued		10,018,300	10,018,300
Preferred Stock Outstanding		10,018,300
Carrying Value		$ 104,140
Liquidation Preference		$ 104,140
Common Stock Issuable Upon Conversion		8,033,914