SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Summary of Common Shares Excluded from EPS Calculations (Details) - shares	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Shares excluded from the calculation of EPS (in shares)	1,246,647	1,697,114
Warrants to purchase common stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Shares excluded from the calculation of EPS (in shares)	720,982	55,344
Options to purchase common stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Shares excluded from the calculation of EPS (in shares)	525,665	376,299
Redeemable convertible preferred stock (as converted into common stock)
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Shares excluded from the calculation of EPS (in shares)	0	1,256,466
Warrants to purchase redeemable convertible preferred stock (as converted into common stock)
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Shares excluded from the calculation of EPS (in shares)	0	9,005