Condensed Consolidated Statements of Redeemable Convertible Preferred Stock and Stockholders' Equity (Deficit) - USD ($) $ in Thousands	Total	Previously Reported [Member]	Redeemable Convertible Preferred Stock [Member]	Redeemable Convertible Preferred Stock [Member] Previously Reported [Member]	Redeemable Convertible Preferred Stock [Member] Recapitalization [Member]	Common Stock [Member]	Common Stock [Member] Previously Reported [Member]	Common Stock [Member] Recapitalization [Member]	Additional Paid-in Capital [Member]	Additional Paid-in Capital [Member] Previously Reported [Member]	Additional Paid-in Capital [Member] Recapitalization [Member]	Accumulated Deficit [Member]	Accumulated Deficit [Member] Previously Reported [Member]
Beginning Balance at Mar. 31, 2020	$ (620,883)	$ (620,883)	$ 755,083	$ 755,083		$ 9	$ 0	$ 9	$ 172,727	$ 172,736	$ (9)	$ (793,619)	$ (793,619)
Beginning Balance, Shares at Mar. 31, 2020			198,274,933	86,443,341	111,831,592	101,652,799	44,318,298	57,334,501
Issuance of common stock upon exercise of stock options	1,139								1,139
Shares Available for Grant, Exercised						676,618
Vesting Early Exercised Stock Options	4,241								4,241
Stock-based compensation expense	11,454								11,454
Net Loss	(35,770)											(35,770)
Ending Balance at Jun. 30, 2020	(639,819)		$ 755,083			$ 9			189,561			(829,389)
Ending Balance, Shares at Jun. 30, 2020			198,274,933			102,329,417
Beginning Balance at Mar. 31, 2020	(620,883)	(620,883)	$ 755,083	$ 755,083		$ 9	$ 0	$ 9	172,727	172,736	(9)	(793,619)	(793,619)
Beginning Balance, Shares at Mar. 31, 2020			198,274,933	86,443,341	111,831,592	101,652,799	44,318,298	57,334,501
Vesting Early Exercised Stock Options	8,482
Net Loss	(71,961)
Ending Balance at Sep. 30, 2020	(659,978)		$ 755,083			$ 9			205,593			(865,580)
Ending Balance, Shares at Sep. 30, 2020			198,274,933			109,648,425
Beginning Balance at Jun. 30, 2020	(639,819)		$ 755,083			$ 9			189,561			(829,389)
Beginning Balance, Shares at Jun. 30, 2020			198,274,933			102,329,417
Issuance of common stock upon exercise of stock options	827								827
Shares Available for Grant, Exercised						437,913
Issuance of common stock related to early exercise of stock options, shares						6,881,095
Vesting Early Exercised Stock Options	4,241								4,241
Stock-based compensation expense	10,964								10,964
Net Loss	(36,191)											(36,191)
Ending Balance at Sep. 30, 2020	(659,978)		$ 755,083			$ 9			205,593			(865,580)
Ending Balance, Shares at Sep. 30, 2020			198,274,933			109,648,425
Beginning Balance at Mar. 31, 2021	(595,619)	(595,619)	$ 837,351	$ 837,351		$ 12	$ 0	$ 12	381,607	381,619	(12)	(977,238)	(977,238)
Beginning Balance, Shares at Mar. 31, 2021			209,181,855	91,198,378	117,983,477	124,529,784	54,292,140	70,237,644
Preferred stock conversion	837,351		$ (837,351)			$ 21			837,330
Preferred stock conversion, shares			(209,181,855)			(209,181,855)
Issuance of common stock upon Merger, net of transaction costs and Merger warrant liability	200,579					$ 5			200,574
Issuance Of Common Stock Upon Merger And Merger Warrant Liability Shares						46,901,747
Issuance of PIPE shares	250,000					$ 3			249,997
Issuance of PIPE shares, shares						25,000,000
Issuance of common stock upon exercise of stock options	$ 2,553								2,553
Shares Available for Grant, Exercised	0					818,479
Stock-based compensation expense	$ 9,704								9,704
Net Loss	(42,026)											(42,026)
Ending Balance at Jun. 30, 2021	662,542		$ 0			$ 41			1,681,765			(1,019,264)
Ending Balance, Shares at Jun. 30, 2021			0			406,431,865
Beginning Balance at Mar. 31, 2021	$ (595,619)	$ (595,619)	$ 837,351	$ 837,351		$ 12	$ 0	$ 12	381,607	$ 381,619	$ (12)	(977,238)	$ (977,238)
Beginning Balance, Shares at Mar. 31, 2021			209,181,855	91,198,378	117,983,477	124,529,784	54,292,140	70,237,644
Shares Available for Grant, Exercised	1,555,196
Vesting Early Exercised Stock Options	$ 0
Net Loss	(58,550)
Ending Balance at Sep. 30, 2021	659,511		$ 0			$ 41			1,695,258			(1,035,788)
Ending Balance, Shares at Sep. 30, 2021			0			407,168,582
Beginning Balance at Jun. 30, 2021	662,542		$ 0			$ 41			1,681,765			(1,019,264)
Beginning Balance, Shares at Jun. 30, 2021			0			406,431,865
Issuance of common stock upon exercise of stock options	2,905								2,905
Shares Available for Grant, Exercised						736,717
Stock-based compensation expense	10,588								10,588
Net Loss	(16,524)											(16,524)
Ending Balance at Sep. 30, 2021	$ 659,511		$ 0			$ 41			$ 1,695,258			$ (1,035,788)
Ending Balance, Shares at Sep. 30, 2021			0			407,168,582