Benefit Plans (Details) In Thousands	9 Months Ended
	Sep. 30, 2011
Summary of share-based award activity
Balance at December 31, 2010	10,449
Options granted	(913)
Restricted stock units granted	(2,784)
Options cancelled	556
Restricted stock units cancelled	951
Options expired	40
Balance at September 30, 2011	8,299