REVENUE FROM CONTRACTS WITH CUSTOMERS - Additional Information (Details) - USD ($) $ in Thousands			1 Months Ended	3 Months Ended			9 Months Ended		10 Months Ended	15 Months Ended
	Jun. 28, 2019	Oct. 09, 2015	Oct. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Apr. 30, 2020	Jul. 31, 2021	Dec. 31, 2019
Contract Balance And Performance Obligations description							The Company had no contract assets and contract liability balances under the license and collaboration agreements at either September 30, 2020 or 2019.
Monthly license payment receivable		$ 5,000
Product sales return allowance liability				$ 0	$ 223	$ 0	$ 223	$ 0
Sales return allowance liability				0	$ 0		0				$ 223
License fees received				$ 300		$ 1,050	$ 2,400	$ 1,050
AD Pharma Agreement | Subsequent event
Monthly license payment receivable			$ 200
Abuse Deterrent Pharma, LLC
Monthly license payment receivable									$ 350
Abuse Deterrent Pharma, LLC | AD Pharma Agreement
Monthly license payment receivable	$ 350								$ 200
Abuse Deterrent Pharma, LLC | AD Pharma Agreement | Subsequent event
Monthly license payment receivable										$ 200