Fair Value Measurements - Additional Information (Details) $ in Thousands			1 Months Ended		9 Months Ended
		Mar. 10, 2020 USD ($)	Oct. 31, 2020 USD ($)	Jun. 30, 2020 USD ($)	Sep. 30, 2020 USD ($)		Dec. 31, 2019 USD ($)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total unrealized gains recorded in accumulated other comprehensive income (loss)					$ 200
Derivative liability							$ 12,449
Reclassification of derivative liability to additional paid-in capital upon achievement of development milestone		$ 29,200
Maximum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Securities contractual term					1 year
Humabs
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Specified clinical development milestones payment				$ 10,000
Estimated fair value of contingent consideration					$ 42,500		$ 14,900
Humabs | Subsequent Event | SARS-CoV-2 Product
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Specified clinical development milestones payment			$ 10,000
Humabs | Measurement Input, Discount Rate | Commercial Milestones
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value contingent consideration measurement input					0.11	[1]	0.13
Humabs | Measurement Input, Discount Rate | Maximum | Clinical and Regulatory Milestones
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value contingent consideration measurement input					0.12	[2]	0.111
Humabs | Measurement Input, Discount Rate | Minimum | Clinical and Regulatory Milestones
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value contingent consideration measurement input					0.10	[2]	0.077
Humabs | Measurement Input Expected Revenue Volatility | Commercial Milestones
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value contingent consideration measurement input					0.60	[1]	0.55
TomegaVax
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Estimated fair value of contingent consideration					$ 9,500		$ 2,700
TomegaVax | Measurement Input Risk Free Interest Rate | Maximum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value embedded derivative estimated using discount rates							0.017
TomegaVax | Measurement Input Risk Free Interest Rate | Minimum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value embedded derivative estimated using discount rates							0.016
TomegaVax | Measurement Input, Discount Rate | Maximum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value contingent consideration measurement input	[3]				0.002
TomegaVax | Measurement Input, Discount Rate | Minimum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value contingent consideration measurement input	[3]				0.000
TomegaVax | Expected Stock Price Volatility
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value contingent consideration measurement input	[3]				0.85
Fair value embedded derivative estimated using discount rates							0.81

[1] Unobservable inputs were weighted based on the relative fair value of the commercial milestone payments

[2] Unobservable inputs were weighted based on the relative fair value of the clinical and regulatory milestone payments.

[3] Unobservable inputs were weighted based on the relative fair value of the underlying milestones.