Summary of Significant Accounting Policies - Additional Information (Details) - USD ($)	12 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2020	Mar. 31, 2019
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Increase in revenue adjustment	$ 9,000,000.0
Decrease in net loss	$ 9,000,000.0
Decreased net loss, basic and diluted	$ (0.02)
Revenue recognized	$ 31,900,000
Deferred revenue for customer services	51,300,000	$ 39,300,000
Total restricted cash	8,600,000	8,400,000
Advertising costs	54,700,000	11,200,000	$ 62,600,000
Impairment Losses	0	0	1,300,000
Deferred Advertising Costs	700,000
Impairment charges	0	0	0
Impairment of long-lived assets	$ 0	0	33,213,000
Stock based compensation expense related to restructuring activities			900,000
Minimum [Member]
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Remaining performance obligation, remaining duration	1 year
Maximum [Member]
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Remaining performance obligation, remaining duration	2 years
ESPP [Member]
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Payroll deductions to participate in plan	15.00%
ESPP [Member] | Class A Common Stock [Member]
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Discount from market price, offering date	85.00%
Discount from market price, purchase date	85.00%
Maximum value of shares per employee	$ 25,000
K I T S
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Revenue recognized	21,900,000	24,100,000	38,000,000.0
Research Services
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Revenue recognized	31,400,000	42,800,000	28,700,000
Remaining performance obligations	67,800,000	61,900,000
Deferred revenue for customer services	11,600,000	31,900,000	48,600,000	$ 48,700,000
Contract with customer liability related party amount	9,200,000	30,100,000
Contract with customer liability revenue recognized related party amount	$ 30,100,000	39,900,000
Consumer services
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Revenue recognized		34,400,000	59,900,000
Deferred revenue for customer services		$ 39,300,000	$ 38,800,000	$ 74,100,000
Supplier Concentration Risk | Revenue Benchmark [Member] | Microarrays
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Percentage of Revenue	100.00%
Supplier Concentration Risk | Revenue Benchmark [Member] | K I T S
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Percentage of Revenue	100.00%
Supplier Concentration Risk | Revenue Benchmark [Member] | Laboratory Services
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Percentage of Revenue	100.00%	100.00%	100.00%
Other charges [Member] | Additions to restructuring plan [Member]
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Impairment loss			$ 12,600,000