CHANGES IN BUSINESS - Restructuring Costs (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018
Restructuring costs rollforward
Beginning balance	$ 3,256
Restructuring charges		$ 5,689
Payments for restructuring	(3,114)	(2,433)
Adjustments	(142)
Ending Balance		3,256
Lease
Restructuring costs rollforward
Beginning balance	367
Restructuring charges		536
Ending Balance		367
Lease \| Other current liabilities
Restructuring costs rollforward
Beginning balance	367
Restructuring charges		536
Payments for restructuring	(225)	(169)
Adjustments	(142)
Ending Balance		367
Severance
Restructuring costs rollforward
Restructuring charges		5,153
Severance \| Severance
Restructuring costs rollforward
Beginning balance	2,889
Restructuring charges		5,153
Payments for restructuring	$ (2,889)	(2,264)
Ending Balance		$ 2,889

Amount of cash payments made as the result of exit or disposal activities. Excludes payments associated with a discontinued operation or an asset retirement obligation.

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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.

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Amount of expense (reversal of expense) which increases (decreases) the restructuring reserve from an adjustment to a previously accrued restructuring liability.

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Carrying amount as of the balance sheet date of known and estimated obligations associated with exit from or disposal of business activities or restructurings pursuant to a duly authorized plan, which are expected to be paid in the next twelve months or in the normal operating cycle if longer. Costs of such activities include those for one-time termination benefits, termination of an operating lease or other contract, consolidating or closing facilities, relocating employees, and costs associated with an ongoing benefit arrangement, but excludes costs associated with the retirement of a long-lived asset.

+ References

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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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