GOODWILL AND INTANGIBLE ASSETS - Goodwill (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2021	Dec. 31, 2020
Goodwill [Roll Forward]
Beginning balance	$ 99,547	$ 99,547
2020 accumulated adjustments		0
Ending balance	145,175	$ 99,547
SkyePharma Holding, Inc.
Goodwill [Roll Forward]
Goodwill arising from acquisition	36,000
Flexion
Goodwill [Roll Forward]
Goodwill arising from acquisition	$ 9,628

Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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Amount of increase in asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized resulting from a business combination.

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Amount of increase (decrease) from foreign currency translation adjustments and purchase accounting adjustments of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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