Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2018	Dec. 31, 2017
Preferred stock, par value	$ 0.0001	$ 0.0001
Preferred stock, shares authorized	2,500,000	2,500,000
Preferred stock, shares issued
Preferred stock, shares outstanding
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares authorized	50,000,000	50,000,000
Common stock, shares issued	7,827,651	7,927,774
Common stock, shares outstanding	7,816,944	7,904,307
Treasury stock, shares outstanding	10,707	23,467
Class A Common Stock [Member]
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares authorized	2,500,000	2,500,000
Common stock, shares issued
Common stock, shares outstanding
Class B Common Stock [Member]
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares authorized	7,500,000	7,500,000
Common stock, shares issued
Common stock, shares outstanding