Common Stock - Schedule of Shares Reserved for Future Issuance (Details) - shares	Dec. 31, 2016	Dec. 31, 2015
Common Stock Capital Shares Reserved For Future Issuance [Line Items]
Shares reserved for future issuance (in shares)	4,133,703	3,596,681
Unvested restricted stock
Common Stock Capital Shares Reserved For Future Issuance [Line Items]
Shares reserved for future issuance (in shares)	22,150	41,657
Restricted stock units
Common Stock Capital Shares Reserved For Future Issuance [Line Items]
Shares reserved for future issuance (in shares)	3,333	150,932
Options to purchase common stock
Common Stock Capital Shares Reserved For Future Issuance [Line Items]
Shares reserved for future issuance (in shares)	3,112,771	2,319,772
Common stock warrants
Common Stock Capital Shares Reserved For Future Issuance [Line Items]
Shares reserved for future issuance (in shares)		926,840
Employee stock purchase plan
Common Stock Capital Shares Reserved For Future Issuance [Line Items]
Shares reserved for future issuance (in shares)	68,609	157,480