Summary of Significant Accounting Policies (Components of Accumulated Other Comprehensive Loss) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	$ 47,392,282	$ 41,653,127
Ending balance	47,494,727	47,392,282
Foreign Currency Translation [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	(709,000)	(764,000)
Net current period change	9,000	55,000
Ending balance	(700,000)	(709,000)
Unrealized gain (loss) on securities [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	11,000	13,000
Net current period change	10,000	(2,000)
Ending balance	21,000	11,000
Accumulated Other Comprehensive Loss [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	(697,664)	(751,293)
Net current period change	19,000	53,000
Ending balance	$ (678,767)	$ (697,664)