Income Taxes (Narrative) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Income Tax Disclosure [Line Items]
U.S. Federal income tax benefit at federal statutory rate	21.00%	34.00%
Effective tax rate
Reduction to deferred tax assest valuation allowance		$ 19,000,000
Expected refund for AMT credit carryforward	$ 200,000
Valuation allowance	34,726,000	32,473,000
Federal net operating loss carryforwards	142,600,000
State net operating loss carryforwards	9,000,000
Research and development tax credit carryforwards	2,438,000	2,338,000
Unrecognized tax benefits	0	0
Unrecognized tax benefits, interest and penalties	$ 0	$ 0
Minimum [Member]
Income Tax Disclosure [Line Items]
U.S. Federal income tax benefit at federal statutory rate	21.00%
Maximum [Member]
Income Tax Disclosure [Line Items]
U.S. Federal income tax benefit at federal statutory rate		35.00%
Scenario, Forecast [Member]
Income Tax Disclosure [Line Items]
Expected refund for AMT credit carryforward			$ 200,000	$ 200,000	$ 200,000