RESTRUCTURING COSTS AND ACCRUALS (Details) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016 USD ($) position	Sep. 30, 2016 USD ($)	Jun. 30, 2016 USD ($)	Mar. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Sep. 30, 2015 USD ($)	Jun. 30, 2015 USD ($)	Mar. 31, 2015 USD ($)	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)
Restructuring Cost and Reserve [Line Items]
Restructuring charges	$ 4,959	$ 5,314	$ (213)	$ 2,777	$ 5,766	$ 0	$ 539	$ 0	$ 12,837	$ 6,305	$ (165)
Tangible Asset Impairment Charges									1,137	0	0
Facilties-related accuals - noncurrent	1,256				647				1,256	647
Restructuring accrual [Roll Forward]
Accrual balance at beginning of year				7,180				2,343	7,180	2,343	8,501
New restructuring charges									11,434	5,766
Revisions of estimated liabilities									266	539	(165)
Accretion									287	226	565
Cash payments									(9,926)	(1,616)	(6,512)
Non-cash write-offs									1,137
Foreign exchange impact on ending balance									(267)	(78)	(46)
Accrual balance at end of period	10,111				7,180				10,111	7,180	2,343
Employee-Related [Member]
Restructuring accrual [Roll Forward]
Accrual balance at beginning of year				5,509				58	5,509	58	2,399
New restructuring charges									10,491	5,766
Revisions of estimated liabilities									(497)	0	0
Accretion									0	0	0
Cash payments									(8,225)	(315)	(2,340)
Foreign exchange impact on ending balance									(260)	0	(1)
Accrual balance at end of period	7,018				5,509				7,018	5,509	58
Facilities-Related [Member]
Restructuring Cost and Reserve [Line Items]
Facilities-related accruals - current	700				1,000				700	1,000
Facilties-related accuals - noncurrent	1,300				600				1,300	600
Restructuring accrual [Roll Forward]
Accrual balance at beginning of year				1,671				$ 2,285	1,671	2,285	6,102
New restructuring charges									943	0
Revisions of estimated liabilities									763	539	(165)
Accretion									287	226	565
Cash payments									(1,701)	(1,301)	(4,172)
Foreign exchange impact on ending balance									(7)	(78)	(45)
Accrual balance at end of period	3,093				1,671				3,093	$ 1,671	$ 2,285
Facilities-Related [Member]
Restructuring accrual [Roll Forward]
Non-cash write-offs									1,137
Employee-Related [Member]
Restructuring accrual [Roll Forward]
Non-cash write-offs									0
2016 Plan [Member] | Employee-Related [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring charges	$ 5,000	$ 2,400	400	$ 2,800	$ 5,800
Number of positions eliminated	156	60		63	111
Restructuring accrual [Roll Forward]
Revisions of estimated liabilities			$ (600)
2016 Plan [Member] | Facilities-Related [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring charges		$ 2,100
Tangible Asset Impairment Charges		1,100
Restructuring Plan 2012 [Member] | Facilities-Related [Member]
Restructuring accrual [Roll Forward]
Revisions of estimated liabilities		$ 800					$ 500
Restructuring Plan 2008 [Member] | Facilities-Related [Member]
Restructuring accrual [Roll Forward]
Accrual balance at end of period	$ 1,400								$ 1,400