BALANCE SHEETS (Parenthetical) - $ / shares	Dec. 31, 2016	Dec. 31, 2015
Stockholders' equity:
Preferred stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Preferred stock authorized (in shares)	2,000,000	2,000,000
Preferred stock, issued (in shares)	0	0
Preferred stock, outstanding (in shares)	0	0
Common stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Common stock, authorized (in shares)	50,000,000	50,000,000
Common stock, issued (in shares)	13,138,007	12,979,536
Common stock, outstanding (in shares)	13,098,080	12,939,609
Treasury stock, at cost (in shares)	24,371	24,371