Restructuring Charges (Details) (USD $) In Thousands, unless otherwise specified	9 Months Ended			9 Months Ended			3 Months Ended	9 Months Ended	12 Months Ended	9 Months Ended
	Sep. 30, 2011	Sep. 30, 2012	Dec. 31, 2011	Sep. 30, 2012 Restructuring Plan 2011	Sep. 30, 2012 Restructuring Plan 2011 Employee separation costs	Sep. 30, 2012 Restructuring Plan 2011 Consolidation of leased facilities	Dec. 31, 2010 Restructuring Plan 2010	Sep. 30, 2012 Restructuring Plan 2010	Dec. 31, 2011 Restructuring Plan 2010	Sep. 30, 2012 Restructuring Plan 2010 Consolidation of leased facilities	Sep. 30, 2012 2009 restructuring plan	Sep. 30, 2012 2009 restructuring plan Employee separation costs	Sep. 30, 2012 2009 restructuring plan Consolidation of leased facilities
Restructuring Charges.
Restructuring charges	$ 17,678						$ 2,300		$ 800
Restructuring Charges
Balance at the beginning of the period		5,714	11,708	8,867	4,530	4,337		2,553		2,553	288	53	235
Utilized - cash				(5,459)	(4,390)	(1,069)		(261)		(261)	(246)	(26)	(220)
Other				(28)	(9)	(19)
Balance at the end of the period		$ 5,714	$ 11,708	$ 3,380	$ 131	$ 3,249		$ 2,292	$ 2,553	$ 2,292	$ 42	$ 27	$ 15