Intangible Assets and Goodwill - Identifiable Intangible Assets (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021
Intangible assets:
Amortization expense	$ 200	$ 200
Finite-lived intangible assets:
Gross Carrying Amount	10,564		$ 11,961
Accumulated  Amortization	(6,531)		(7,191)
Intangible Assets, Net	4,033		4,770
Proprietary adjuvant technology
Finite-lived intangible assets:
Gross Carrying Amount	7,278		8,239
Accumulated  Amortization	(3,245)		(3,469)
Intangible Assets, Net	4,033		4,770
Collaboration agreements
Finite-lived intangible assets:
Gross Carrying Amount	3,286		3,722
Accumulated  Amortization	(3,286)		(3,722)
Intangible Assets, Net	$ 0		$ 0