NATURE OF BUSINESS AND BASIS OF PRESENTATION (Details) $ in Thousands			3 Months Ended								12 Months Ended
	Feb. 03, 2020 USD ($) shares	Jan. 21, 2020	Dec. 31, 2019 USD ($)	Sep. 30, 2019 USD ($)	Jun. 30, 2019 USD ($)	Mar. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Sep. 30, 2018 USD ($)	Jun. 30, 2018 USD ($)	Mar. 31, 2018 USD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)
Subsidiary, Sale of Stock [Line Items]
Net loss			$ 9,875	$ 9,268	$ 12,287	$ 3,828	$ 3,066	$ 2,360	$ 1,913	$ 1,592	$ 35,258	$ 8,931
Accumulated deficit			$ 50,970				$ 15,712				$ 50,970	$ 15,712
Subsequent Event
Subsidiary, Sale of Stock [Line Items]
Reverse stock split		3.01581
Subsequent Event | IPO
Subsidiary, Sale of Stock [Line Items]
Number of shares sold | shares	12,174,263
Number of shares issued, options exercised | shares	1,587,947
Gross proceeds	$ 231,311
Proceeds from stock issuance, net	$ 212,429
Number of shares issued upon conversion | shares	21,499,770