PUBLIC OFFERING AND PRIVATE PLACEMENT - Narrative (Details) - USD ($) $ / shares in Units, $ in Millions			1 Months Ended	9 Months Ended
	Aug. 21, 2019	Aug. 16, 2019	Nov. 30, 2020	Sep. 30, 2021	Dec. 31, 2020
Class of Stock [Line Items]
Common stock, issued (in shares)			1,040,000	8,465,549	8,385,650
Shares issuable per warrants (in shares)			3,109,378
Warrants to purchase aggregate shares of common stock (in shares)			4,149,378
Shares purchased by selling common stock and pre-funded warrant (in shares)			1
Common stock, par value (in dollars per share)			$ 0.001	$ 0.01	$ 0.01
Warrant exercise price (in dollars per share)			$ 6.50
Expiration period			5 years
Proceeds from issuance of stock			$ 25.0
Proceeds from issuance of redeemable convertible preferred stock in a public offering, net	$ 53.8
Proceeds upon entering into private placement agreement				$ 11.2
Maximum
Class of Stock [Line Items]
Price of each share of common stock and accompanying common warrant (in dollars per share)			$ 6.025
Minimum
Class of Stock [Line Items]
Price of each share of common stock and accompanying common warrant (in dollars per share)			$ 6.024
Series 1 redeemable convertible non-voting preferred stock
Class of Stock [Line Items]
Shares issuable per warrants (in shares)				10
Series 2 Preferred Stock
Class of Stock [Line Items]
Expiration period				2 years 6 months
Public Warrants, Private Warrants And Stock Options
Class of Stock [Line Items]
Total offering costs related to warrants and options				$ 3.0
Public Offering
Class of Stock [Line Items]
Shares issuable under warrants (in shares)		5,750,000
Price per share (in dollars per share)		$ 100.00
Public Offering | Series 1 redeemable convertible non-voting preferred stock
Class of Stock [Line Items]
Number of shares of common stock sold in offering (in shares)		575,000
Warrants exercise price (in dollars per share)		$ 130.00
Public Offering | Common Stock
Class of Stock [Line Items]
Shares issuable per warrants (in shares)		10
Shares issuable under warrants (in shares)		0
Warrants exercise price (in dollars per share)		$ 13.00
Notice period for percentage change		61 days
Public Offering | Common Stock | Maximum
Class of Stock [Line Items]
Warrants, limitations on ownership after exercise		19.99%
Public Offering | Common Stock | Minimum
Class of Stock [Line Items]
Warrants, limitations on ownership after exercise		9.99%
Private Placement | Series 2 Preferred Stock
Class of Stock [Line Items]
Number of shares of common stock sold in offering (in shares)		350,000		350,000
Shares issuable under warrants (in shares)		2,800,000
Price per share (in dollars per share)		$ 100.00
Warrants exercise price (in dollars per share)		$ 10.00
Private Placement | Series 3 Preferred Stock
Class of Stock [Line Items]
Number of shares of common stock sold in offering (in shares)		250,000		250,000
Private Placement | Preferred Stock
Class of Stock [Line Items]
Shares issuable under warrants (in shares)		875,000
Price per share (in dollars per share)		$ 140.00
Warrants exercise price (in dollars per share)		$ 14.00