Share-Based Compensation Plans (Schedule Of Activity In Nonvested Restricted Stock Unit Awards) (Details) (Restricted Stock Units [Member], USD $)	12 Months Ended
	Dec. 31, 2011
Restricted Stock Units [Member]
Number of shares outstanding, beginning balance	559,507
Number of options, granted	147,094
Number of shares, vested	(65,526)
Number of shares, forfeited	(93,803)
Number of shares outstanding, ending balance	547,272
Weighted average grant date fair value outstanding, beginning balance	$ 78.29
Weighted average grant date fair value, granted	$ 91.07
Weighted average grant date fair value, vested	$ 67.27
Weighted average grant date fair value, forfeited	$ 83.01
Weighted average grant date fair value outstanding, ending balance	$ 82.36