Subsequent Event (Details) (USD $) In Thousands, except Share data, unless otherwise specified	9 Months Ended			1 Months Ended			3 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Dec. 31, 2010	Oct. 31, 2011 Employee separation and related costs Restructuring	Oct. 31, 2011 Consolidation of leased facilities Restructuring Employee	Oct. 31, 2011 Restructuring	Sep. 30, 2011 Repurchase of shares	Oct. 31, 2011 Repurchase of shares
Subsequent event
Restructuring charges	$ 17,678	$ 2,250		$ 2,100	$ 4,000	$ 6,100
Number of employees terminated					100
Purchase of common stock	1,964,500						950,000
Value of common stock purchased	$ 232,355		$ 220,161				$ 10,400
Average price of common stock purchased (in dollars per share)							$ 10.92
Common stock authorized for repurchase							900,000	4,000,000