COMMON STOCK AND STOCKHOLDERS' EQUITY - SCHEDULE OF PREFERRED STOCK CONVERTIBLE INTO COMMON STOCK (Details)	1 Months Ended
	Mar. 31, 2015 shares	Sep. 30, 2016 shares	Dec. 31, 2015 shares
Class Of Stock [Line Items]
Preferred stock, shares outstanding (in shares)	20,454,489	0	0
Stock split ratio	1
Number of Shares, As Converted	20,673,680
Series A Preferred Stock
Class Of Stock [Line Items]
Preferred stock, shares outstanding (in shares)	1,319,940
Stock split ratio	1.0088
Number of Shares, As Converted	1,331,507
Series B Preferred Stock
Class Of Stock [Line Items]
Preferred stock, shares outstanding (in shares)	988,411
Stock split ratio	1.0148
Number of Shares, As Converted	1,003,071
Series C Preferred Stock
Class Of Stock [Line Items]
Preferred stock, shares outstanding (in shares)	4,019,524
Stock split ratio	1.0192
Number of Shares, As Converted	4,096,561
Series D Preferred Stock
Class Of Stock [Line Items]
Preferred stock, shares outstanding (in shares)	5,308,875
Stock split ratio	1.0218
Number of Shares, As Converted	5,424,802
Series E Preferred Stock
Class Of Stock [Line Items]
Preferred stock, shares outstanding (in shares)	2,439,058
Stock split ratio	1.0000
Number of Shares, As Converted	2,439,058
Series F Preferred Stock
Class Of Stock [Line Items]
Preferred stock, shares outstanding (in shares)	2,685,997
Stock split ratio	1.0000
Number of Shares, As Converted	2,685,997
Series G Preferred Stock
Class Of Stock [Line Items]
Preferred stock, shares outstanding (in shares)	3,692,684
Stock split ratio	1.0000
Number of Shares, As Converted	3,692,684