Earnings Per Share - Earnings Per Share (Details) - USD ($)	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016
Earnings Per Share [Abstract]
Net income	$ (655,000)	$ 1,202,000	$ 2,846,000	$ 659,000	$ 545,000	$ 1,473,000	$ 3,267,000	$ 565,000	$ 4,052,479	$ 5,850,998
Weighted average shares outstanding									3,356,383	3,327,867
Effect of dilutive employee stock options									368,220	249,956
Denominator for dilutive earnings per share									3,724,603	3,577,823
Basic earnings per share	$ (.20)	$ .36	$ .85	$ .20	$ .16	$ .44	$ .98	$ .17	$ 1.21	$ 1.76
Dilutive earnings per share	$ (.16)	$ .32	$ .75	$ .18	$ .15	$ .40	$ .91	$ .16	$ 1.09	$ 1.64