Recapitalization (Details) $ / shares in Units, $ in Thousands					12 Months Ended
	Jun. 17, 2021	Jun. 16, 2021 USD ($) $ / shares shares	Jun. 16, 2021 $ / shares shares	Feb. 04, 2021 USD ($) tradingDay $ / shares shares	Mar. 31, 2024 USD ($) $ / shares shares	Mar. 31, 2023 USD ($) $ / shares shares	Mar. 31, 2022 USD ($)
Reverse Recapitalization [Line Items]
Acquired ownership percentage		100.00%	100.00%
Proceeds from issuance of common stock, consummation of Merger | $		$ 559,700
Proceeds from issuance of common stock merger | $		309,700
Proceeds from PIPE | $		250,000			$ 0	$ 0	$ 250,000
Transaction costs | $		$ 33,700					33,726
Common stock, par value (in usd per share) | $ / shares		$ 0.0001	$ 0.0001		$ 0.0001	$ 0.0001
Number of shares called by each warrant (in shares) | shares		1	1
Period after closing date				1 year
Stock price trigger (in usd per share) | $ / shares				$ 12.00
Trading days | tradingDay				20
Trading days, period after Business Combination | tradingDay				30
Days after Business Combination				150 days
Percentage of founder shares released from lock-up				70.00%
Anniversary of closing date				1 year
Related Party
Reverse Recapitalization [Line Items]
Proceeds from PIPE | $					$ 0	$ 0	$ 25,000
Founder shares
Reverse Recapitalization [Line Items]
Shares restricted for transfer (in shares) | shares				12,713,750
VG Acquisition Sponsor LLC
Reverse Recapitalization [Line Items]
Lockup period for shares	7 years
Earn-out shares, percentage				50.00%
Restricted Stock Units
Reverse Recapitalization [Line Items]
Shares conversion ratio		2.293698169
Common Stock Class A
Reverse Recapitalization [Line Items]
Shares conversion ratio		2.293698169
Common stock, par value (in usd per share) | $ / shares		$ 0.0001	$ 0.0001
Lock up for Class A common stock in connection with the Merger				180 days
Common stock, shares outstanding (in shares) | shares					323,394,807	293,020,474
Trading days				20 days
Number of trading days after commencing				30 days
Subscription shares issued (in shares) | shares				25,000,000
Common Stock Class A | PIPE Investment
Reverse Recapitalization [Line Items]
Gross proceeds | $				$ 250,000
Common Stock Class A | VG Acquisition Sponsor LLC
Reverse Recapitalization [Line Items]
Common stock, price per share (in usd per share) | $ / shares				$ 10.00
Common Stock Class A | The Anne Wojcicki Foundation | Related Party
Reverse Recapitalization [Line Items]
Subscription shares issued (in shares) | shares				2,500,000
Common Stock Class A | VG Acquisition Sponsor LLC
Reverse Recapitalization [Line Items]
Trading days				20 days
Number of trading days after commencing				30 days
Common Stock Class A | VG Acquisition Sponsor LLC | Minimum
Reverse Recapitalization [Line Items]
Share price thresholds release from lock up (in usd per share) | $ / shares				$ 12.50
Common Stock Class A | VG Acquisition Sponsor LLC | Maximum
Reverse Recapitalization [Line Items]
Share price thresholds release from lock up (in usd per share) | $ / shares				$ 15.00
Common Stock Class A | Restricted Stock Units
Reverse Recapitalization [Line Items]
Shares conversion ratio		2.293698169
Common Stock Class B
Reverse Recapitalization [Line Items]
Shares conversion ratio		2.293698169	2.293698169
Common stock, par value (in usd per share) | $ / shares		$ 0.0001	$ 0.0001
Common stock, shares outstanding (in shares) | shares					166,724,586	168,179,488
Common Stock Class B | Founder shares
Reverse Recapitalization [Line Items]
Percentage of shares restricted for transfer				70.00%
Common Stock Class B | VGAC
Reverse Recapitalization [Line Items]
Remaining ownership percentage acquired				30.00%
Common Stock Class B | VG Acquisition Sponsor LLC
Reverse Recapitalization [Line Items]
Common stock, shares outstanding (in shares) | shares				3,814,125