Summary of Significant Accounting Policies - Additional Information (Details) $ / shares in Units, $ in Thousands	1 Months Ended	3 Months Ended	12 Months Ended
	Sep. 30, 2015 USD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2019 USD ($) item segment $ / shares shares	Dec. 31, 2018 USD ($) shares	Dec. 31, 2017 shares	Jun. 30, 2019 USD ($)	Jan. 01, 2019 USD ($)
Summary of Significant Accounting Policies [Line Items]
Number of shares excluded from the computation of net loss per share | shares			4,992,792	2,975,481	2,325,670
Restricted cash current		$ 2,947	$ 2,947	$ 10,847
Purchase price held in escrow		1,500	$ 1,500
Number of operating segments | segment			1
Number of reporting units | item			1
Impairment to goodwill			$ 0	0
Accruals for interest or penalties related to income tax matters		0	0	0
Foreign currency translation adjustment		12,500	12,500	11,200
Operating Lease, Liability		$ 11,266	$ 11,266
Lease, Practical Expedient, Lessor Single Lease Component [true false]		true	true
Lease, Practical Expedients, Package [true false]			true
Catalent Maryland, Inc
Summary of Significant Accounting Policies [Line Items]
Purchase price held in escrow						$ 1,500
Write-off of right-of-use assets			$ 8,200
Write-off of lease liabilities			$ 12,700
Maximum [Member]
Summary of Significant Accounting Policies [Line Items]
Property and equipment useful life			7 years
Intangible assets useful life			20 years
Vesting period			4 years
Minimum [Member]
Summary of Significant Accounting Policies [Line Items]
Property and equipment useful life			3 years
Intangible assets useful life			7 years
Vesting period			6 months
Bill Melinda Gates Foundation [Member]
Summary of Significant Accounting Policies [Line Items]
Grant Agreement			$ 89,100
Bill Melinda Gates Foundation [Member] | Maximum [Member]
Summary of Significant Accounting Policies [Line Items]
Grant Agreement	$ 89,100			89,100
Hhs Barda Contract Award [Member]
Summary of Significant Accounting Policies [Line Items]
Revenue		$ 7,500
Accounting Standards Update 2016-02 [Member]
Summary of Significant Accounting Policies [Line Items]
Operating Lease, Right-of-Use Asset							$ 12,000
Operating Lease, Liability							$ 22,000
Convertible Debt Securities [Member]
Summary of Significant Accounting Policies [Line Items]
Number of shares excluded from the computation of net loss per share | shares			2,385,800
Convertible Notes Initial Conversion Price Per Share | $ / shares			$ 136.20
Security Deposit [Member]
Summary of Significant Accounting Policies [Line Items]
Restricted cash current		400	$ 400	1,000
Grant Agreement [Member]
Summary of Significant Accounting Policies [Line Items]
Restricted cash current		$ 1,400	$ 1,400	$ 10,800