Restructuring Reserves 2010 Restructuring Plan (Details) (USD $)	3 Months Ended	12 Months Ended		23 Months Ended	42 Months Ended
	Mar. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2011	Jun. 30, 2011
Restructuring Reserve [Roll Forward]
Restructuring charges	$ 2,219,000
Number of positions eliminated			200
Restructuring Plan 2010 [Member]
Restructuring Reserve [Roll Forward]
Restructuring reserve	2,598,000			19,478,000
Adjustments to reserves	2,000			1,615,000
Cash charges	(85,000)			(17,642,000)
Non - cash settlements	(135,000)			(996,000)
Impact of changes in exchange rates	11,000			143,000
Restructuring reserve	2,391,000	2,598,000		2,598,000
Restructuring charges		1,600,000	19,500,000
Restructuring charges that have been paid					17,700,000
Restructuring reserve included in accrued expenses and other current liabilities	1,700,000
Restructuring Plan 2010 [Member] | Accrued exit and disposal obiligations [Member]
Restructuring Reserve [Roll Forward]
Restructuring reserve included in accrued exit and disposal obligations	600,000
Restructuring Plan 2010 [Member] | Employee Severance [Member]
Restructuring Reserve [Roll Forward]
Restructuring reserve	7,000			14,098,000
Adjustments to reserves	1,000			826,000
Cash charges	(8,000)			(14,990,000)
Non - cash settlements	0			0
Impact of changes in exchange rates	0			73,000
Restructuring reserve	0	7,000		7,000
Restructuring charges		14,900,000
Restructuring Plan 2010 [Member] | Facility Closing [Member]
Restructuring Reserve [Roll Forward]
Restructuring reserve	2,591,000			5,380,000
Adjustments to reserves	1,000			789,000
Cash charges	(77,000)			(2,652,000)
Non - cash settlements	(135,000)			(996,000)
Impact of changes in exchange rates	11,000			70,000
Restructuring reserve	2,391,000	2,591,000		2,591,000
Restructuring charges			$ 6,200,000