RESTRUCTURING COSTS AND ACCRUALS (Details) (USD $)	3 Months Ended		3 Months Ended		12 Months Ended	3 Months Ended	12 Months Ended	3 Months Ended		12 Months Ended	3 Months Ended			12 Months Ended		12 Months Ended	3 Months Ended		12 Months Ended	3 Months Ended				12 Months Ended
	Mar. 31, 2012	Dec. 31, 2011	Dec. 31, 2011 employee related [Member] Non-Acquisition-Related [Member] RestructuringPlan2011 [Member] position	Mar. 31, 2012 Employee Severance [Member] Non-Acquisition-Related [Member] RestructuringPlan2011 [Member]	Dec. 31, 2011 Employee Severance [Member] Non-Acquisition-Related [Member] RestructuringPlan2011 [Member]	Dec. 31, 2010 Employee Severance [Member] Non-Acquisition-Related [Member] 2010 Restructuring Plan [Member] position	Dec. 31, 2011 Employee Severance [Member] Non-Acquisition-Related [Member] 2010 Restructuring Plan [Member]	Dec. 31, 2008 Employee Severance [Member] Non-Acquisition-Related [Member] Restructuring Plan 2008 [Member] position	Mar. 31, 2012 Employee Severance [Member] Acquisition-Related [Member]	Dec. 31, 2010 Employee Severance [Member] Acquisition-Related [Member] 2010 Restructuring Plan [Member] employee	Mar. 31, 2012 Non-Acquisition-Related [Member] Employee Severance [Member]	Mar. 31, 2012 Non-Acquisition-Related [Member] Facilities-Related [Member]	Mar. 31, 2012 Restructuring Charges Total [Member] Non-Acquisition-Related [Member] RestructuringPlan2011 [Member]	Dec. 31, 2011 Restructuring Charges Total [Member] Non-Acquisition-Related [Member] 2010 Restructuring Plan [Member]	Mar. 31, 2012 Facilities-Related [Member]	Dec. 31, 2011 Facilities-Related [Member] Non-Acquisition-Related [Member] RestructuringPlan2011 [Member]	Mar. 31, 2012 Facilities-Related [Member] Non-Acquisition-Related [Member] 2010 Restructuring Plan [Member]	Dec. 31, 2010 Facilities-Related [Member] Non-Acquisition-Related [Member] 2010 Restructuring Plan [Member]	Dec. 31, 2011 Facilities-Related [Member] Non-Acquisition-Related [Member] 2010 Restructuring Plan [Member]	Mar. 31, 2012 Facilities-Related [Member] Non-Acquisition-Related [Member] Restructuring Plan 2008 [Member]	Dec. 31, 2008 Facilities-Related [Member] Non-Acquisition-Related [Member] Restructuring Plan 2008 [Member] facility	Mar. 31, 2012 Facilities-Related [Member] Acquisition-Related [Member]	Mar. 31, 2012 Facilities-Related [Member] Acquisition-Related [Member] 2010 Restructuring Plan [Member]	Dec. 31, 2010 Facilities-Related [Member] Acquisition-Related [Member] 2010 Restructuring Plan [Member] facility
Restructuring Cost and Reserve [Line Items]
Number of positions eliminated			190			145		820		24
Severance costs					$ 9,100,000	$ 9,200,000		$ 35,200,000		$ 2,000,000
Restructuring costs, closure of facilities																500,000		1,400,000	1,000,000		12,800,000
Non-cash restructuring charge - write down of inventory																100,000			100,000		2,700,000
Restructuring and related cost minimum expected cost													9,000,000
Total restructuring charges expected to be recorded under the plan													10,000,000
Restructuring charges related to the Plan														10,000,000
Number of facilities closed																					18			3
Restructuring accrual [Roll Forward]
Accrual balance at beginning of year	11,337,000								0		4,422,000	6,445,000										470,000
Revisions of estimated liabilities	168,000			400,000			1,500,000		0		(362,000)	360,000					100,000		300,000	200,000	4,300,000	170,000	200,000
Accretion	50,000								0		0	50,000										0
Cash payments for employee-related charges	(2,826,000)								0		(2,826,000)	0										0
Cash payments for facilities, net of sublease income	(1,133,000)								0		0	(1,024,000)										(109,000)
Foreign exchange impact on ending balance	61,000								0		35,000	26,000										0
Accrual balance at end of period	7,657,000								0		1,269,000	5,857,000										531,000
Facilities-related accruals - current															3,500,000
Facilities-related accruals - non-current	$ 2,914,000	$ 3,185,000													$ 2,900,000