Income Taxes (Details Textual) - USD ($) $ in Thousands		12 Months Ended
Jan. 09, 2020	Dec. 31, 2020	Dec. 31, 2019
Income Taxes (Textual)
Net operating loss and credit carryovers		$ 63,700
Valuation allowance		21,700	$ 4,200
Net operating loss after application		$ 1,400
Merger, description	The Company acquired NOL's from Proteon of $41.6 million. These NOLs were determined to be impaired by $12.4 million, with an annual limitation of $0.5 million on the remaining $29.2 million of NOLs. The general business credits of $3.6 million acquired in the merger were determined to be fully impaired.

21,700

$ 4,200

The Company acquired NOL's from Proteon of $41.6 million. These NOLs were determined to be impaired by $12.4 million, with an annual limitation of $0.5 million on the remaining $29.2 million of NOLs. The general business credits of $3.6 million acquired in the merger were determined to be fully impaired.