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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QUARTERLY RESULTS (UNAUDITED) - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended					12 Months Ended
	Sep. 30, 2018	Jun. 30, 2018	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Restructuring Cost and Reserve [Line Items]
Restructuring charges			$ 11,500	$ 4,600	$ 2,700	$ (136)	$ 18,828	$ 40,438
IBM Patent Litigation Case
Restructuring Cost and Reserve [Line Items]
Gain (Loss) Related to Litigation Settlement	$ 40,400	$ 75,000				$ 34,600