Goodwill and Other Intangible Assets - Identifiable Intangible Assets (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Intangible assets:
Amortization expense	$ 300	$ 500
Finite-lived intangible assets:
Gross Carrying Amount	12,332		$ 13,208
Accumulated  Amortization	(7,305)		(7,483)
Intangible Assets, Net	5,027		5,725
Proprietary adjuvant technology
Finite-lived intangible assets:
Gross Carrying Amount	8,496		9,099
Accumulated  Amortization	(3,469)		(3,374)
Intangible Assets, Net	5,027		5,725
Collaboration agreements
Finite-lived intangible assets:
Gross Carrying Amount	3,836		4,109
Accumulated  Amortization	(3,836)		(4,109)
Intangible Assets, Net	$ 0		$ 0