Share-Based Compensation Plans (Schedule Of Activity In Nonvested Restricted Stock Awards) (Details) (Restricted Stock [Member], USD $)	12 Months Ended
	Dec. 31, 2011
Restricted Stock [Member]
Number of shares outstanding, beginning balance	1,033,268
Number of options, granted	271,863
Number of shares, vested	(171,725)
Number of shares, forfeited	(11,641)
Number of shares outstanding, ending balance	1,121,765
Weighted average grant date fair value outstanding, beginning balance	$ 84.48
Weighted average grant date fair value, granted	$ 85.09
Weighted average grant date fair value, vested	$ 82.21
Weighted average grant date fair value, forfeited	$ 85.03
Weighted average grant date fair value outstanding, ending balance	$ 84.97