Common Stock Data (Sales Price Of Common Stock Reported By New York Stock Exchange) (Details) (USD $)	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2010	Sep. 30, 2010
High [Member]
Sales price of common stock	$ 64.40	$ 62.75	$ 54.11	$ 48.70	$ 51.93	$ 52.92	$ 49.92	$ 48.85
Low [Member]
Sales price of common stock	$ 58.15	$ 50.91	$ 43.61	$ 40.00	$ 41.44	$ 45.36	$ 44.65	$ 42.00