The Merger (Schedule of company’s consolidated statement of operations and unaudited proforma information) (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Business Acquisition [Line Items]
General and administrative expenses	$ 1,845,000	$ 3,758,000	$ 5,989,000	$ 7,220,000
Net loss	(5,769,000)	$ (6,955,000)	(15,557,000)	$ (14,893,000)
AmpliPhi Biosciences Corporation [Member]
Business Acquisition [Line Items]
Research and development expenses	292,000		430,000
General and administrative expenses	499,000		845,000
Net loss	$ 791,000		$ 1,275,000