Employee Benefit Plans (Schedule Of Employee Option Plan) (Details) (USD $)	9 Months Ended
	Sep. 30, 2011
Employee Benefit Plans [Abstract]
Options, Outstanding at beginning of period	1,272,739
Options, Granted	494,885
Options, Exercised	(140,792)
Options, Forfeited	(44,449)
Options, Expired	(1,198)
Options, Outstanding at end of period	1,581,185
Weighted Average Exercise Price, Outstanding at beginning of period	$ 38.77
Weighted Average Exercise Price, Granted	$ 61.51
Weighted Average Exercise Price, Exercised	$ 37.77
Weighted Average Exercise Price, Forfeited	$ 51.83
Weighted Average Exercise Price, Expired	$ 43.00
Weighted Average Exercise Price, Outstanding at end of period	$ 45.61