Investment in Non-Consolidated Affiliate (Details) $ in Thousands				3 Months Ended		9 Months Ended	12 Months Ended
	Sep. 30, 2021 USD ($)	Jun. 18, 2021 USD ($)	May 22, 2020 USD ($)	Sep. 30, 2021 USD ($)	Mar. 31, 2021 USD ($)	Sep. 30, 2021 USD ($)	Dec. 31, 2020 USD ($)	May 22, 2021 USD ($)	Jan. 31, 2021 USD ($)	May 31, 2020 USD ($)
Schedule of Equity Method Investments [Line Items]
Carrying amount of investment in non-consolidated affiliate	$ 1,906,387			$ 1,906,387		$ 1,906,387	$ 988,331
Investment in non-consolidated affiliate	0			0		0	29,555
Gain on settlement of line of credit						4,700
Inivata
Schedule of Equity Method Investments [Line Items]
VIE, gain (loss)						$ 109,600
Fair value of previously-held equity interest(1)	64,900	$ 64,906
Fair value of Purchase Option(1)	$ 74,300	74,300
Measurement period adjustments, net assets acquired		17,750		$ 17,800
Variable Interest Entity, Not Primary Beneficiary
Schedule of Equity Method Investments [Line Items]
Carrying amount of investment in non-consolidated affiliate							29,600
Unrealized loss on investment in non-consolidated affiliate							4,000
Preference Shares | Variable Interest Entity, Not Primary Beneficiary
Schedule of Equity Method Investments [Line Items]
Carrying amount of investment in non-consolidated affiliate							25,000
Investment in non-consolidated affiliate									$ 30,000
Preference Shares | Variable Interest Entity, Not Primary Beneficiary | Measurement Input, Price Volatility
Schedule of Equity Method Investments [Line Items]
Purchase option, measurement input (as a percent)						0.84
Preference Shares | Variable Interest Entity, Not Primary Beneficiary | Measurement Input, Risk Free Interest Rate
Schedule of Equity Method Investments [Line Items]
Purchase option, measurement input (as a percent)						0.0017
Preference Shares | Variable Interest Entity, Not Primary Beneficiary | Measurement Input, Expected Dividend Rate
Schedule of Equity Method Investments [Line Items]
Purchase option, measurement input (as a percent)						0
Purchase Option | Variable Interest Entity, Not Primary Beneficiary
Schedule of Equity Method Investments [Line Items]
Carrying amount of investment in non-consolidated affiliate							$ 4,600
Purchase Option | Variable Interest Entity, Not Primary Beneficiary | Measurement Input, Price Volatility
Schedule of Equity Method Investments [Line Items]
Purchase option, measurement input (as a percent)						0.84	0.84
Purchase Option | Variable Interest Entity, Not Primary Beneficiary | Measurement Input, Risk Free Interest Rate
Schedule of Equity Method Investments [Line Items]
Purchase option, measurement input (as a percent)						0.0017	0.0017
Purchase Option | Variable Interest Entity, Not Primary Beneficiary | Measurement Input, Expected Dividend Rate
Schedule of Equity Method Investments [Line Items]
Purchase option, measurement input (as a percent)						0	0
Inivata Limited
Schedule of Equity Method Investments [Line Items]
Net unrealized loss for remeasurement of investment					$ 5,000
Amount outstanding under line of credit		10,300
Inivata Limited | Line of Credit
Schedule of Equity Method Investments [Line Items]
Line of credit facility maximum borrowing capacity			$ 15,000					$ 15,000
Interest rate per annum (as a percent)						0.00%
Imputed interest rate (as a percent)									8.33%
Loan with imputed interest, discount									$ 5,000
Additional investment in non-consolidated affiliate									5,000
Present value of loan receivable with imputed interest									$ 10,000
Amount outstanding under line of credit		10,300
Inivata Limited | Variable Interest Entity, Not Primary Beneficiary
Schedule of Equity Method Investments [Line Items]
Investment in minority interest		29,600	25,000		29,600					$ 25,000
Transaction costs			600
Inivata Limited | Variable Interest Entity, Not Primary Beneficiary | Line of Credit
Schedule of Equity Method Investments [Line Items]
Interest income from loan receivable						$ 400
Inivata Limited | Preference Shares | Variable Interest Entity, Not Primary Beneficiary
Schedule of Equity Method Investments [Line Items]
Investment in minority interest		25,000	19,600		25,000
Inivata Limited | Purchase Option | Variable Interest Entity, Not Primary Beneficiary
Schedule of Equity Method Investments [Line Items]
Investment in minority interest		$ 4,600	$ 6,000		$ 4,600