Stock Option And Deferred Compensation Plans (Summary Of Activity Under Stock Option Plans) (Details) (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2011 years
Stock Option And Deferred Compensation Plans [Abstract]
Number of Shares, Outstanding as of January 1, 2011	4,718,435
Number Of Shares, Options Granted	778,413
Number of Shares, Options Exercised	(860,513)
Number of Shares, Options Forfeited	(176,894)
Number of Shares, Options Expired	(281,573)
Number of Shares, Outstanding as of December 31, 2011	4,177,868
Weighted-Average Exercise Price, Outstanding as of January 1, 2011	$ 15.59
Weighted-Average Exercise Price, Options Granted	$ 21.03
Weighted-Average Exercise Price, Options Exercised	$ 11.74
Weighted-Average Exercise Price, Options Forfeited	$ 16.42
Weighted-Average Exercise Price, Options Expired	$ 24.50
Weighted-Average Exercise Price, Outstanding as of December 31, 2011	$ 16.77
Weighted-Average Remaining Contractual Life, Outstanding as of December 31, 2011 (in years)	4.23
Aggregate Intrinsic Value, Outstanding as of December 31, 2011	$ 45,709
Number of Shares, Vested and unvested expected to vest as of December 31, 2011	4,105,602
Weighted-Average Exercise Price, Vested and unvested expected to vest as of December 31, 2011	$ 16.73
Weighted-Average Remaining Contractual Life, Vested and unvested expected to vest as of December 31, 2011 (in years)	4.20
Aggregate Intrinsic Value, Vested and expected to vest as of December 31, 2011	45,102
Number of Shares, Options exercisable as of December 31, 2011	2,804,009
Weighted-Average Exercise Price, Options exercisable as of December 31, 2011	$ 16.02
Weighted-Average Remaining Contractual Life, Options exercisable as of December 31, 2011 (in years)	3.54
Aggregate Intrinsic Value, Options exercisable as of December 31, 2011	$ 33,303