REVENUE - Royalties & Milestone Revenue (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Royalties and milestones \| Collegium Pharmaceutical Inc \| Amended Commercialization Agreement
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Expense related to third-party royalties	$ 0.5	$ 0.5	$ 1.0	$ 0.9

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

No definition available.

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