RESTRUCTURING CHARGES - Schedule of Restructuring Activities (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Restructuring costs
Employee compensation costs	$ 0	$ 260	$ 876	$ 5,695
Equity compensation costs	0	0	0	999
Other exit costs	0	8	213	93
Total restructuring costs	$ 0	$ 268	$ 1,089	$ 6,787

Severance Costs, Stock-Based Compensation

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- Definition

Amount of other expenses associated with exit or disposal activities pursuant to an authorized plan. Excludes expenses associated with a discontinued operation or an asset retirement obligation.

+ References

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Amount of expenses associated with exit or disposal activities pursuant to an authorized plan. Excludes expenses related to a discontinued operation or an asset retirement obligation.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
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Amount of expenses for special or contractual termination benefits provided to current employees involuntarily terminated under a benefit arrangement associated exit or disposal activities pursuant to an authorized plan. Excludes expenses related to one-time termination benefits, a discontinued operation or an asset retirement obligation.

+ References

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