Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2017	Dec. 31, 2016
Statement Of Financial Position [Abstract]
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares authorized	200,000,000	200,000,000
Common stock, shares issued	9,616,992	9,275,062
Common stock, shares outstanding	9,481,992	9,275,062
Treasury stock, shares at cost	135,000	0