Condensed Consolidated Statements of Mezzanine Equity and Stockholders' Equity (Deficit) (Unaudited) - USD ($) $ in Thousands	Total	PIPE Investment	Class A Common Stock Warrants	Common Stock	Common Stock PIPE Investment	Common Stock Class A Common Stock Warrants	Additional Paid-In Capital	Additional Paid-In Capital PIPE Investment	Additional Paid-In Capital Class A Common Stock Warrants	Accumulated Other Comprehensive Income (Loss)	Accumulated Deficit	Redeemable Convertible Preferred Stock	Redeemable Class A Common Stock	Previously Reported	Previously Reported Common Stock	Previously Reported Additional Paid-In Capital	Previously Reported Accumulated Other Comprehensive Income (Loss)	Previously Reported Accumulated Deficit	Previously Reported Redeemable Convertible Preferred Stock	Previously Reported Redeemable Class A Common Stock	Revision of Prior Period, Adjustment	Revision of Prior Period, Adjustment Common Stock	Revision of Prior Period, Adjustment Additional Paid-In Capital	Revision of Prior Period, Adjustment Redeemable Convertible Preferred Stock	Revision of Prior Period, Adjustment Redeemable Class A Common Stock
Mezzanine equity, beginning balance (in shares) at Dec. 31, 2019												84,514,191	737,058						186,573,651	1,627,132				102,059,460	890,074
Mezzanine equity, beginning balance at Dec. 31, 2019												$ 186,741	$ 4,500						$ 186,741	$ 4,500
Increase (Decrease) in Temporary Equity [Roll Forward]
Issuance of Series D convertible preferred stock, net of issuance costs (in shares)												4,537,700
Issuance of Series D convertible preferred stock, net of issuance costs												$ 31,511
Conversion of convertible securities (in shares)													(737,058)
Conversion of convertible securities													$ (4,500)
Mezzanine equity, ending balance (in shares) at Mar. 31, 2020												89,051,891	0
Mezzanine equity, ending balance at Mar. 31, 2020												$ 218,252	$ 0
Beginning balance (in shares) at Dec. 31, 2019				51,588,612											113,887,093							62,298,481
Beginning balance at Dec. 31, 2019	$ (139,793)			$ 0			$ 13,383			$ 2	$ (153,178)			$ (139,793)	$ 0	$ 13,383	$ 2	$ (153,178)			$ 0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Conversion of convertible securities (in shares)				737,058
Conversion of convertible securities	4,500						4,500
Exercise of vested stock options (in shares)				226
Early exercise of unvested stock options (in shares)				226
Vesting of early exercised stock options	11						11
Forfeiture of unvested early exercised shares (in shares)				(46,242)
Stock-based compensation	1,404						1,404
Other comprehensive income	(42)									(42)
Net loss	(6,033)										(6,033)
Ending balance (in shares) at Mar. 31, 2020				52,279,880
Ending balance at Mar. 31, 2020	$ (139,953)			$ 0			19,298			(40)	(159,211)
Mezzanine equity, beginning balance (in shares) at Dec. 31, 2019												84,514,191	737,058						186,573,651	1,627,132				102,059,460	890,074
Mezzanine equity, beginning balance at Dec. 31, 2019												$ 186,741	$ 4,500						$ 186,741	$ 4,500
Mezzanine equity, ending balance (in shares) at Dec. 31, 2020	93,328,118											93,328,118	0						206,031,290	0				112,703,172
Mezzanine equity, ending balance at Dec. 31, 2020	$ 249,962											$ 249,962	$ 0						$ 249,962	$ 0
Beginning balance (in shares) at Dec. 31, 2019				51,588,612											113,887,093							62,298,481
Beginning balance at Dec. 31, 2019	(139,793)			$ 0			13,383			2	(153,178)			(139,793)	$ 0	13,383	2	(153,178)			$ 0
Ending balance (in shares) at Dec. 31, 2020				52,967,106											116,930,602							63,963,496
Ending balance at Dec. 31, 2020	$ (146,874)			$ 5			24,424			(11)	(171,292)			$ (146,874)	$ 0	$ 24,429	$ (11)	$ (171,292)				$ 5	$ (5)
Increase (Decrease) in Temporary Equity [Roll Forward]
Pre-closing stock repurchase, net of exercise of vested options (in shares)												206,511
Pre-closing stock repurchase, net of exercise of vested options												$ 125
Conversion of convertible securities (in shares)												(93,121,607)
Conversion of convertible securities												$ (249,837)
Mezzanine equity, ending balance (in shares) at Mar. 31, 2021	0											0	0
Mezzanine equity, ending balance at Mar. 31, 2021	$ 0											$ 0	$ 0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Pre-closing stock repurchase, net of exercise of vested options (in shares)				(1,817,519)
Pre-closing stock repurchase, net of exercise of vested options	(21,902)						(21,902)
Conversion of convertible securities (in shares)				93,121,607		1,867,292
Conversion of convertible securities	249,837		$ 21,678	$ 9			249,828		$ 21,678
Repayment of related-party promissory notes associated with vested shares	854						854
Forfeiture of related-party promissory notes (in shares)				(370,734)
Conversion of Series D preferred stock warrants to Class A common warrants	1,160						1,160
Issuance of common stock upon Merger, net of transaction costs and merger warrant liability (in shares)				23,892,244
Issuance of common stock upon Merger, net of transaction costs and Merger warrants liability	129,659			$ 2			129,657
Issuance of PIPE shares (in shares)					7,500,000
Issuance of PIPE shares		$ 75,000			$ 1			$ 74,999
Issuance of earn-out shares to common stockholders (in shares)				14,153,520
Issuance of earn-out shares to common stockholders	1			$ 1
Exercise of vested stock options (in shares)				37,887
Exercise of vested stock options	80						80
Vesting of early exercised stock options	54						54
Warrant expense in connection with Merger	154						154
Stock-based compensation	34,230						34,230
Other comprehensive income	(61)									(61)
Net loss	(51,404)										(51,404)
Ending balance (in shares) at Mar. 31, 2021				191,351,403
Ending balance at Mar. 31, 2021	$ 292,466			$ 18			$ 515,216			$ (72)	$ (222,696)