NET LOSS PER COMMON SHARE - Summary of Potentially Dilutive Securities (Details) - shares	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Stock options
Anti-dilutive securities
Potentially dilutive securities excluded from the computations of diluted weighted-average shares outstanding	2,326,801	1,452,149	281,029
Warrants
Anti-dilutive securities
Potentially dilutive securities excluded from the computations of diluted weighted-average shares outstanding	2,445	2,445	18,809
All series of convertible redeemable preferred stock
Anti-dilutive securities
Potentially dilutive securities excluded from the computations of diluted weighted-average shares outstanding			6,552,820
Restricted Stock Award
Anti-dilutive securities
Potentially dilutive securities excluded from the computations of diluted weighted-average shares outstanding	41,741