Condensed Consolidated Statements of Operations (unaudited) - USD ($) shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Income Statement [Abstract]
Total revenue	$ 183.5	$ 179.3	$ 364.7	$ 344.2
Costs and expenses:
Cost of testing revenue	57.8	49.7	117.0	97.7
Research and development expense	21.2	20.3	43.7	41.5
Selling, general, and administrative expense	140.7	127.1	292.4	237.7
Legal charges pending settlement	77.5	0.0	77.5	0.0
Goodwill and long-lived asset impairment charges	0.0	0.0	0.0	10.7
Total costs and expenses	297.2	197.1	530.6	387.6
Operating loss	(113.7)	(17.8)	(165.9)	(43.4)
Other income (expense):
Interest income	0.5	0.4	1.2	0.5
Interest expense	(0.5)	(0.6)	(1.0)	(1.5)
Other	(2.4)	0.1	(3.0)	0.1
Total other expense, net	(2.4)	(0.1)	(2.8)	(0.9)
Loss before income tax	(116.1)	(17.9)	(168.7)	(44.3)
Income tax expense (benefit)	0.0	(3.8)	2.1	(9.7)
Net loss	$ (116.1)	$ (14.1)	$ (170.8)	$ (34.6)
Net loss per share:
Basic (dollars per share)	$ (1.42)	$ (0.18)	$ (2.10)	$ (0.43)
Diluted (dollars per share)	$ (1.42)	$ (0.18)	$ (2.10)	$ (0.43)
Weighted average shares outstanding:
Basic (shares)	81.7	80.4	81.5	80.3
Diluted (shares)	81.7	80.4	81.5	80.3
Revenue from contract with customer, product and service, extensible enumeration	Testing [Member]	Testing [Member]	Testing [Member]	Testing [Member]
Cost, product and service, extensible enumeration	Testing [Member]	Testing [Member]	Testing [Member]	Testing [Member]