RESTRUCTURING CHARGES - Schedule of Restructuring Activities (Details) - USD ($)	3 Months Ended	6 Months Ended
Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Restructuring costs
Employee compensation costs	$ 0	$ 5,814,000	$ 0	$ 14,593,000
Other exit costs	0	0	0	238,000
Total restructuring costs	$ 0	$ 5,814,000	$ 0	$ 14,831,000

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.

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