Acquisitions (Details) - USD ($) $ in Thousands	Oct. 06, 2017	Sep. 30, 2018	Dec. 31, 2017
Fair value of tangible assets acquired and liabilities assumed [Abstract]
Goodwill		$ 49,130	$ 49,130
Sanofi [Member]
Summary of total purchase price [Abstract]
Amount of cash paid to Sanofi	$ 117,500
Fair value of contingent purchase consideration	2,200
Total purchase price	119,700
Fair value of tangible assets acquired and liabilities assumed [Abstract]
Inventory	74,876
Property, plant and equipment	19,995
Total fair value of tangible assets acquired and liabilities assumed	94,871
Acquired intangible asset	16,700
Goodwill	8,129
Total purchase price	$ 119,700
ACAM2000 [Member]
Acquisitions [Abstract]
Term of contract under acquisition	10 years
Value of contract	$ 425,000
Amount for deliveries of product to the SNS	160,000
Upfront cash payment	97,500
Amount of payment for manufacturing related milestones	20,000
Amount of payment for regulatory related milestones	$ 7,500		$ 7,500
Fair value of tangible assets acquired and liabilities assumed [Abstract]
Amortization period of intangible asset	10 years
ACAM2000 [Member] | Discount Rate [Member]
Fair value of tangible assets acquired and liabilities assumed [Abstract]
Present value discount rate	15.50%