Revenue - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023	Mar. 31, 2024
Disaggregation of Revenue [Line Items]
Revenue recognized from unreturned kits	$ 5.4	$ 4.3	$ 9.4	$ 8.9
Contract assets	$ 0.0		$ 0.0		$ 0.0
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-10-01
Disaggregation of Revenue [Line Items]
Revenue to be recognized, percentage	86.00%		86.00%
Remaining performance obligation, expected timing of satisfaction, period	12 months		12 months
Consumer services
Disaggregation of Revenue [Line Items]
Deferred revenue for customer services	$ 47.2		$ 47.2		52.3
Revenue recognized	10.8		32.4
Research services
Disaggregation of Revenue [Line Items]
Deferred revenue for customer services	22.6		22.6		22.5
Revenue recognized	0.4		1.4
Remaining performance obligations	26.7		26.7
Research services | Related Party
Disaggregation of Revenue [Line Items]
Deferred revenue for customer services	21.7		21.7		$ 21.0
Revenue recognized	$ 0.3		$ 0.5