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BASIS OF PRESENTATION (Details) - USD ($) $ in Thousands		9 Months Ended
BASIS OF PRESENTATION (Details) - USD ($) $ in Thousands	Nov. 08, 2019	Sep. 30, 2018	Sep. 30, 2019	Dec. 31, 2018
Issuance of stock
Accumulated deficit			$ 142,727	$ 84,835
Cash and cash equivalents			$ 98,192	$ 147,840
Proceeds from issuance of common stock, net of issuance costs		$ 101,607
Follow-on shelf public offering \| Subsequent Event
Issuance of stock
Proceeds from issuance of common stock, net of issuance costs	$ 134,700