Balance Sheets (Parenthetical) - $ / shares	Sep. 30, 2015	Dec. 31, 2014
Common stock
Par value per share (in USD per share)	$ 0.001	$ 0.001
Shares issued (in shares)	20,142,715	16,878,817
Shares outstanding (in shares)	20,142,715	16,878,817
Shares authorized (in shares)	100,000,000	100,000,000
Preferred stock
Par value per share (in USD per share)	$ 0.001	$ 0.001
Shares issued (in shares)	0	0
Shares outstanding (in shares)	0	0
Shares authorized (in shares)	10,000,000	10,000,000