Restructuring Charges (Details) (USD $)	9 Months Ended		3 Months Ended	9 Months Ended		3 Months Ended		9 Months Ended	3 Months Ended	9 Months Ended			3 Months Ended	9 Months Ended
	Sep. 30, 2013	Sep. 30, 2013 Restructuring Plan 2013	Jun. 30, 2013 Restructuring Plan 2013 Employee separation costs item	Sep. 30, 2013 Restructuring Plan 2013 Employee separation costs	Sep. 30, 2013 Restructuring Plan 2013 Consolidation of leased facilities	Jun. 30, 2013 Restructuring Plan 2012	Dec. 31, 2012 Restructuring Plan 2012	Sep. 30, 2013 Restructuring Plan 2012 Employee separation costs	Jun. 30, 2013 Restructuring Plan 2011	Sep. 30, 2013 Restructuring Plan 2011	Sep. 30, 2013 Restructuring Plan 2011 Employee separation costs	Sep. 30, 2013 Restructuring Plan 2011 Consolidation of leased facilities	Dec. 31, 2010 Restructuring Plan 2010	Sep. 30, 2013 Restructuring Plan 2010 Consolidation of leased facilities
Restructuring Charges.
Number of employees terminated			40
Restructuring charges	$ (75,000)	$ 1,552,000		$ 1,452,000	$ 100,000								$ 2,300,000
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		(235,000)		(235,000)				(4,969,000)		(648,000)	(12,000)	(636,000)		(291,000)
Acceleration of share-based compensation in additional paid-in capital		(357,000)		(357,000)
Other		39,000		39,000				(1,747,000)		(98,000)	(98,000)
Balance at the end of the period	4,841,000	999,000		899,000	100,000			192,000		1,769,000	7,000	1,762,000		1,881,000
Estimated related cost savings due to restructuring plan							20,000,000
Amount of expense reversed						$ 800,000			$ 800,000