Acquisitions - Narrative (Details) - USD ($)				3 Months Ended		12 Months Ended
	Sep. 30, 2021	Jun. 18, 2021	Apr. 07, 2021	Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2021	May 31, 2020
Business Acquisition [Line Items]
Common stock, par value (in dollars per share)				$ 0.001		$ 0.001
Inivata Limited
Business Acquisition [Line Items]
Net unrealized loss for remeasurement of investment					$ 5,000,000
Amount outstanding under line of credit		$ 10,300,000
Variable Interest Entity, Not Primary Beneficiary | Inivata Limited
Business Acquisition [Line Items]
Investment in minority interest							$ 25,000,000
Consideration paid to other shareholders		390,000,000
Marketing Assets
Business Acquisition [Line Items]
Amortization period of acquired intangible assets				4 years		4 years
Trademarks
Business Acquisition [Line Items]
Amortization period of acquired intangible assets				15 years		15 years
Trade Name
Business Acquisition [Line Items]
Amortization period of acquired intangible assets				5 years		5 years
Trapelo Health
Business Acquisition [Line Items]
Percentage of voting interests acquired (as a percent)			100.00%
Cash consideration paid			$ 35,591,000
Payments to acquire business, adjustments			600,000
Common stock issued for consideration			$ 29,174,000
Shares of common stock issued as consideration (in shares)			597,712
Stock price per share on closing date (in dollars per share)			$ 48.81
Amortization period of acquired intangible assets			9 years 9 months 18 days
Goodwill, tax deductible amount			$ 0
Trapelo Health | Identifiable intangible assets - developed technology(1)
Business Acquisition [Line Items]
Intangible assets, useful life			10 years
Trapelo Health | Marketing Assets
Business Acquisition [Line Items]
Intangible assets, useful life			4 years
Inivata
Business Acquisition [Line Items]
Cash consideration paid		398,594,000
Payments to acquire business, adjustments		$ 8,600,000
Amortization period of acquired intangible assets		14 years 10 months 24 days
Goodwill, tax deductible amount		$ 0
Line of credit settled as consideration for acquisition		15,000,000
Fair value of previously-held equity interest(1)	$ 64,900,000	64,906,000
Fair value of Purchase Option(1)	$ 74,300,000	74,300,000
Gain on investment in and loan receivable from non-consolidated affiliate, net						$ 109,300,000
Increase in goodwill from deferred income tax liabilities		60,994,000
Inivata | Clinical Services
Business Acquisition [Line Items]
Goodwill acquired		238,400,000
Inivata | Pharma Services
Business Acquisition [Line Items]
Goodwill acquired		$ 33,000,000.0
Inivata | Identifiable intangible assets - developed technology(1)
Business Acquisition [Line Items]
Intangible assets, useful life		15 years
Inivata | Trademarks
Business Acquisition [Line Items]
Intangible assets, useful life		15 years
Inivata | Trade Name
Business Acquisition [Line Items]
Intangible assets, useful life		5 years