Net Loss Per Common Share - Summary of outstanding shares of common stock equivalents excluded from the computation of diluted net loss per share (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Weighted average shares outstanding:
Total	749,377	3,103,380	1,381,007	3,103,380
Convertible preferred stock
Weighted average shares outstanding:
Total		1,480,042	414,267	1,480,042
Convertible preferred stock warrants
Weighted average shares outstanding:
Total		1,285,838	326,134	1,285,838
Common stock warrants
Weighted average shares outstanding:
Total	359,714		285,655
Options
Weighted average shares outstanding:
Total	389,663	337,500	354,951	337,500