Consolidated Balance Sheets (Parenthetical) - USD ($)	Dec. 31, 2019	Dec. 31, 2018
Consolidated Balance Sheets [Abstract]
Allowance for doubtful accounts receivable, current	$ 39,169	$ 40,000
Preferred stock, par value per share	$ 0.001	$ 0.001
Preferred stock, shares authorized	2,000,000	2,000,000
Preferred stock, shares issued	0	0
Common stock, par value per share	$ 0.01	$ 0.01
Common stock, shares authorized	10,000,000	10,000,000
Common stock, shares issued	3,926,491	3,926,491
Common stock, shares outstanding	2,906,609	2,861,008
Treasury stock, shares	1,019,882	1,065,483