Restructuring Charges (Details) (USD $)			3 Months Ended
	Mar. 31, 2012	Dec. 31, 2011	Mar. 31, 2012 Restructuring Plan 2011	Mar. 31, 2012 Restructuring Plan 2011 Employee separation costs	Mar. 31, 2012 Restructuring Plan 2011 Consolidation of leased facilities	Mar. 31, 2012 Restructuring Plan 2010	Dec. 31, 2010 Restructuring Plan 2010	Mar. 31, 2012 Restructuring Plan 2010 Consolidation of leased facilities	Mar. 31, 2012 2009 restructuring plan	Mar. 31, 2012 2009 restructuring plan Employee separation costs	Mar. 31, 2012 2009 restructuring plan Consolidation of leased facilities
Restructuring Charges.
Restructuring charges							$ 2,300,000
Restructuring Charges
Balance at the beginning of the period	7,914,000	11,708,000	8,867,000	4,530,000	4,337,000	2,553,000		2,553,000	288,000	53,000	235,000
Utilized - cash			(3,476,000)	(3,140,000)	(336,000)	(99,000)		(99,000)	(204,000)	(26,000)	(178,000)
Other			15,000	4,000	11,000
Balance at the end of the period	$ 7,914,000	$ 11,708,000	$ 5,376,000	$ 1,386,000	$ 3,990,000	$ 2,454,000		$ 2,454,000	$ 84,000	$ 27,000	$ 57,000