Revenues (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Revenue from Contract with Customer [Abstract]
Long-term receivable	$ 1,521,700		$ 1,521,700
Accrued expenses, non-current	106,500		106,500
Accumulated deficit			(12,811,000)
Net earnings	1,447,500	$ 70,400	1,543,300	$ 114,400
Cumulative effect of accounting change			96,100
Accumulated deficit	$ (11,171,600)		$ (11,171,600)