Income Taxes (Components of Deferred Tax Assets) (Details) - USD ($)	Dec. 31, 2020	Dec. 31, 2019
Deferred Tax Assets, Net [Abstract]
Net operating loss carry-forwards	$ 31,243,000	$ 26,291,000
Capitalized research and development	15,789,000	15,262,000
Stock-based compensation	2,087,000	1,358,000
Depreciation and amortization	1,405,000	1,632,000
Lease accounting	3,478,000	801,000
Other	989,000	981,000
Total deferred tax assets before valuation allowance	54,991,000	46,325,000
Less: valuation allowance	(51,972,000)	(45,670,000)
Total deferred tax assets after valuation allowance	3,019,000	655,000
Deferred Tax Liabilities, Net [Abstract]
Right-of-use asset	(3,019,000)	(655,000)
In-process research and development	(3,077,000)	(3,077,000)
Total deferred tax liabilities	6,096,000	3,732,000
Net deferred tax liability	$ (3,077,000)	$ (3,077,000)