Investment in Non-Consolidated Affiliate (Details)	May 22, 2020 USD ($) installment	Sep. 30, 2020 USD ($)	Dec. 31, 2019 USD ($)
Schedule of Equity Method Investments [Line Items]
Carrying amount of investment in non-consolidated affiliate		$ 959,428,000	$ 709,506,000
Variable Interest Entity, Not Primary Beneficiary
Schedule of Equity Method Investments [Line Items]
Number of installment payments | installment	2
Carrying amount of investment in non-consolidated affiliate		25,600,000
Variable Interest Entity, Not Primary Beneficiary | Preference Shares
Schedule of Equity Method Investments [Line Items]
Carrying amount of investment in non-consolidated affiliate		19,200,000
Variable Interest Entity, Not Primary Beneficiary | Purchase Option
Schedule of Equity Method Investments [Line Items]
Carrying amount of investment in non-consolidated affiliate		5,800,000
Variable Interest Entity, Not Primary Beneficiary | Transaction Costs
Schedule of Equity Method Investments [Line Items]
Carrying amount of investment in non-consolidated affiliate		$ 600,000
Affiliated Entity | Strategic Alliance With Inivata Limited
Schedule of Equity Method Investments [Line Items]
Line of credit facility maximum borrowing capacity	$ 15,000,000
Stated interest rate (as a percent)	0.00%
Affiliated Entity | Variable Interest Entity, Not Primary Beneficiary
Schedule of Equity Method Investments [Line Items]
Investment in minority interest	$ 25,000,000