Computation of Earnings Per Share (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Basic and diluted earnings per share [Abstract]
Net income	$ 7,399,200	$ 1,221,700
Weighted average shares outstanding for the period (in shares)	1,449,576	1,566,699
Basic earnings per share (in dollars per share)	$ 5.10	$ 0.78
Diluted earnings per share (in dollars per share)	$ 5.10	$ 0.78
Number of potentially dilutive shares outstanding (in shares)	0	0