Summary of Significant Accounting Policies - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands		12 Months Ended
	Jun. 16, 2021	Mar. 31, 2024	Mar. 31, 2023	Mar. 31, 2022
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Revenue		$ 219,638	$ 299,489	$ 271,893
Net loss		666,704	311,656	217,490
Total restricted cash		$ 8,400	8,400
Membership fee period one		1 month
Membership fee period two		3 months
Membership fee period three		12 months
Advertising costs		$ 37,500	49,100	54,700
Deferred advertising costs		400	1,600
Proceeds from Merger				309,700
Proceeds from PIPE	$ 250,000	0	0	250,000
Cash and cash equivalents		$ 216,488	$ 386,849	$ 553,182
Minimum
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Internal use software, useful life		2 years
Maximum
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Internal use software, useful life		4 years
Supplier Concentration Risk | Cost of Goods and Service, Product and Service Benchmark | Microarrays
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Concentration risk, percentage		100.00%	100.00%	100.00%
Supplier Concentration Risk | Cost of Goods and Service, Product and Service Benchmark | Kits
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Concentration risk, percentage		100.00%	100.00%	100.00%
Supplier Concentration Risk | Cost of Goods and Service, Product and Service Benchmark | Laboratory Services
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Concentration risk, percentage		100.00%	100.00%	100.00%
Change In Total Project Resources
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Revenue				$ 9,000
Net loss				$ 9,000
Net loss per share, basic (in usd per share)				$ 0.02
Net loss per share, diluted (in usd per share)				$ 0.02