Restructuring Charges (Details) (USD $)	3 Months Ended	6 Months Ended	3 Months Ended	6 Months Ended	3 Months Ended	6 Months Ended	3 Months Ended	6 Months Ended	3 Months Ended		6 Months Ended	3 Months Ended	6 Months Ended		12 Months Ended	6 Months Ended	12 Months Ended	3 Months Ended	12 Months Ended	3 Months Ended		18 Months Ended
	Jun. 30, 2013	Jun. 30, 2013	Jun. 30, 2013 Restructuring Plan 2013	Jun. 30, 2013 Restructuring Plan 2013	Jun. 30, 2013 Restructuring Plan 2013 Employee separation costs item	Jun. 30, 2013 Restructuring Plan 2013 Employee separation costs	Jun. 30, 2013 Restructuring Plan 2013 Consolidation of leased facilities	Jun. 30, 2013 Restructuring Plan 2013 Consolidation of leased facilities	Jun. 30, 2013 Restructuring Plan 2012	Dec. 31, 2012 Restructuring Plan 2012	Jun. 30, 2013 Restructuring Plan 2012 Employee separation costs	Jun. 30, 2013 Restructuring Plan 2011	Jun. 30, 2013 Restructuring Plan 2011	Jun. 30, 2013 Restructuring Plan 2011 Employee separation costs	Dec. 31, 2011 Restructuring Plan 2011 Employee separation costs	Jun. 30, 2013 Restructuring Plan 2011 Consolidation of leased facilities	Dec. 31, 2011 Restructuring Plan 2011 Lease abandonment costs	Dec. 31, 2010 Restructuring Plan 2010	Dec. 31, 2011 Restructuring Plan 2010	Dec. 31, 2010 Restructuring Plan 2010 Employee separation costs	Dec. 31, 2010 Restructuring Plan 2010 Consolidation of leased facilities	Jun. 30, 2013 Restructuring Plan 2010 Consolidation of leased facilities
Restructuring Charges.
Number of employees terminated					40
Restructuring charges	$ (75,000)	$ (75,000)	$ 1,552,000	$ 1,552,000	$ 1,452,000	$ 1,452,000	$ 100,000	$ 100,000							$ 19,200,000		$ 4,300,000	$ 2,300,000	$ 800,000	$ 100,000	$ 2,200,000
Restructuring Charges
Balance at the beginning of the period		12,295,000									6,908,000		3,215,000	117,000		3,098,000						2,172,000
Adjustment for sub-lease													(700,000)			(700,000)
Utilized - cash											(4,472,000)		(377,000)	(12,000)		(365,000)						(195,000)
Acceleration of share-based compensation in additional paid-in capital				(357,000)		(357,000)
Other				(4,000)		(4,000)					(1,532,000)		(98,000)	(98,000)
Balance at the end of the period	6,112,000	6,112,000	1,191,000	1,191,000	1,091,000	1,091,000	100,000	100,000			904,000	2,040,000	2,040,000	7,000		2,033,000						1,977,000
Estimated related cost savings due to restructuring plan										20,000,000
Amount of expense reversed									$ 800,000			$ 800,000