STOCKHOLDERS' EQUITY (Tables)

12 Months Ended

Dec. 31, 2018

Stockholders' Equity Note [Abstract]

Schedule of Repurchase Agreements

The following table presents the number of shares excluded from the calculation of diluted net loss per share attributable to common stockholders for the periods below:

	Year Ended December 31, 2017	Year Ended December 31, 2018
Common stock warrants	3,730,255	3,385,100
Common stock options	1,082,490	1,255,280
Non-vested restricted stock unit awards	1,476,858	1,921,594
Total shares excluded from net loss per share attributable to common stockholders	6,289,603	6,561,974