Goodwill and Other Intangible Assets (Schedule of Identifiable Intangible Assets) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 13,189	$ 11,935
Accumulated Amortization	(5,316)	(2,710)
Intangible Assets, Net	7,873	9,225
Collaboration agreements [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	4,103	3,713
Accumulated Amortization	(3,310)	(1,306)
Intangible Assets, Net	793	2,407
Proprietary adjuvant technology [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	9,086	8,222
Accumulated Amortization	(2,006)	(1,404)
Intangible Assets, Net	$ 7,080	$ 6,818