Stock Plans (Schedule Of Unrecognized Compensation Cost) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total unrecognized compensation cost, net of estimated forfeitures	$ 54,419	$ 62,928	$ 80,524
Stock Option Plans [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total unrecognized compensation cost, net of estimated forfeitures			218
Restricted Stock And Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total unrecognized compensation cost, net of estimated forfeitures	$ 54,419	$ 62,928	$ 80,306