Significant Accounting Policies (Revenues) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Long-term receivable	$ 1,352,200
Accrued expenses, non-current	94,700
Accumulated deficit	(12,811,000)
Net earnings	1,655,400	381,200
Cumulative effect of accounting change	96,100
Accumulated deficit	(11,059,500)	$ (12,811,000)
Topic 606 [Member]
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Long-term receivable	1,521,700
Accrued expenses, non-current	$ 106,500