Condensed Consolidated Statements of Convertible Preferred Stock and Stockholders’ Equity (Deficit) - USD ($)	Total	Founders Preferred Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Income (Loss)	Accumulated Deficit	Series A Convertible Preferred Stock	Series X Convertible Preferred Stock	Class A Common Stock	Class A Common Stock Common Stock	Class B Common Stock	Class B Common Stock Common Stock
Beginning balance (in shares) at Dec. 31, 2019						94,818,151	0
Beginning balance at Dec. 31, 2019						$ 244,743,000	$ 0
Increase (Decrease) in Temporary Equity [Roll Forward]
Issuance of convertible preferred stock for cash, net of issuance costs (in shares)							17,065,536
Issuance of convertible preferred stock for cash, net of issuance costs							$ 164,111,000
Ending balance (in shares) at Sep. 30, 2020						94,818,151	17,065,536
Ending balance at Sep. 30, 2020						$ 244,743,000	$ 164,111,000
Beginning balance (in shares) at Dec. 31, 2019		26,206,837
Beginning balance at Dec. 31, 2019	$ (211,730,000)	$ 3,000	$ 10,457,000	$ (1,000)	$ (222,203,000)				$ 14,000		$ 0
Beginning balance (in shares) at Dec. 31, 2019									139,635,890		0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Share-based compensation	4,738,000		4,738,000
Other comprehensive income	(19,000)			(19,000)
Net loss	(72,227,000)				(72,227,000)
Ending balance (in shares) at Sep. 30, 2020		26,206,837
Ending balance at Sep. 30, 2020	(279,238,000)	$ 3,000	15,195,000	(20,000)	(294,430,000)				$ 14,000		$ 0
Ending balance (in shares) at Sep. 30, 2020									139,635,890		0
Beginning balance (in shares) at Jun. 30, 2020						94,818,151	0
Beginning balance at Jun. 30, 2020						$ 244,743,000	$ 0
Increase (Decrease) in Temporary Equity [Roll Forward]
Issuance of convertible preferred stock for cash, net of issuance costs (in shares)							17,065,536
Issuance of convertible preferred stock for cash, net of issuance costs							$ 164,111,000
Ending balance (in shares) at Sep. 30, 2020						94,818,151	17,065,536
Ending balance at Sep. 30, 2020						$ 244,743,000	$ 164,111,000
Beginning balance (in shares) at Jun. 30, 2020		26,206,837
Beginning balance at Jun. 30, 2020	(249,305,000)	$ 3,000	13,889,000	8,000	(263,219,000)				$ 14,000		$ 0
Beginning balance (in shares) at Jun. 30, 2020									139,635,890		0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Share-based compensation	1,306,000		1,306,000
Other comprehensive income	(28,000)			(28,000)
Net loss	(31,211,000)				(31,211,000)
Ending balance (in shares) at Sep. 30, 2020		26,206,837
Ending balance at Sep. 30, 2020	(279,238,000)	$ 3,000	15,195,000	(20,000)	(294,430,000)				$ 14,000		$ 0
Ending balance (in shares) at Sep. 30, 2020									139,635,890		0
Beginning balance (in shares) at Dec. 31, 2020						0	0
Beginning balance at Dec. 31, 2020						$ 0	$ 0
Ending balance (in shares) at Sep. 30, 2021						0	0
Ending balance at Sep. 30, 2021						$ 0	$ 0
Beginning balance (in shares) at Dec. 31, 2020		0
Beginning balance at Dec. 31, 2020	148,741,000	$ 0	733,175,000	34,000	(584,501,000)				$ 22,000		$ 11,000
Beginning balance (in shares) at Dec. 31, 2020									218,818,037		105,118,203
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of Class A common stock upon exercise of stock options and vesting of restricted stock units (in shares)									19,585,787
Issuance of Class A common stock upon exercise of stock options and vesting of restricted stock units	496,974,000		496,972,000						$ 2,000
Vendor payments in shares in lieu of cash (in shares)									291,940
Vendor payments in shares in lieu of cash	4,848,000		4,848,000
Acquisition of Optogration, Inc. (in shares)									370,034
Acquisition of Optogration, Inc.	6,527,000		6,527,000
Issuance of earn-out shares (in shares)									10,242,703
Issuance of earn-out shares	(1,000)		(2,000)						$ 1,000		$ 6,970,467
Conversion of Class B common stock into Class A common stock (in shares)									10,500,000		(10,500,000)
Conversion of Class B common stock into Class A common stock	0								$ 1,000		$ (1,000)
Share-based compensation	46,168,000		46,168,000
Payments of employee taxes related to vested restricted stock units	(140,000)		(140,000)
Cash received from Gores on settlement of recapitalization of escrow	10,000		10,000
Other comprehensive income	66,000			66,000
Net loss	(164,093,000)				(164,093,000)
Ending balance (in shares) at Sep. 30, 2021		0
Ending balance at Sep. 30, 2021	539,100,000	$ 0	1,287,558,000	100,000	(748,594,000)				$ 26,000		$ 10,000
Ending balance (in shares) at Sep. 30, 2021								259,808,501	259,808,501	101,588,670	101,588,670
Beginning balance (in shares) at Jun. 30, 2021						0	0
Beginning balance at Jun. 30, 2021						$ 0	$ 0
Ending balance (in shares) at Sep. 30, 2021						0	0
Ending balance at Sep. 30, 2021						$ 0	$ 0
Beginning balance (in shares) at Jun. 30, 2021		0
Beginning balance at Jun. 30, 2021	547,016,000	$ 0	1,244,228,000	7,000	(697,254,000)				$ 24,000		$ 11,000
Beginning balance (in shares) at Jun. 30, 2021									236,483,687		105,118,203
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of Class A common stock upon exercise of stock options and vesting of restricted stock units (in shares)									1,920,137
Issuance of Class A common stock upon exercise of stock options and vesting of restricted stock units	1,547,000		1,547,000
Vendor payments in shares in lieu of cash (in shares)									291,940
Vendor payments in shares in lieu of cash	4,848,000		4,848,000
Acquisition of Optogration, Inc. (in shares)									370,034
Acquisition of Optogration, Inc.	6,527,000		6,527,000
Issuance of earn-out shares (in shares)									10,242,703
Issuance of earn-out shares	(1,000)		(2,000)						$ 1,000		$ 6,970,467
Conversion of Class B common stock into Class A common stock (in shares)									10,500,000		(10,500,000)
Conversion of Class B common stock into Class A common stock									$ 1,000		$ (1,000)
Share-based compensation	30,410,000		30,410,000
Other comprehensive income	93,000			93,000
Net loss	(51,340,000)				(51,340,000)
Ending balance (in shares) at Sep. 30, 2021		0
Ending balance at Sep. 30, 2021	$ 539,100,000	$ 0	$ 1,287,558,000	$ 100,000	$ (748,594,000)				$ 26,000		$ 10,000
Ending balance (in shares) at Sep. 30, 2021								259,808,501	259,808,501	101,588,670	101,588,670