Summary Of Significant Accounting Policies (Calculation Of Basic And Diluted Earnings Per Share) (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Jul. 31, 2013	Apr. 30, 2013	Jan. 31, 2013	Oct. 31, 2012	Jul. 31, 2012	Apr. 30, 2012	Jan. 31, 2012	Oct. 31, 2011	Jul. 31, 2013	Jul. 31, 2012	Jul. 31, 2011
Summary Of Significant Accounting Policies [Abstract]
Weighted average shares - basic									148,273,904	150,286,403	154,392,740
Diluted share equivalents									2,181,000	2,655,000	2,804,000
Weighted average shares - diluted									150,455,193	152,940,605	157,196,918
Net earnings for basic and diluted earnings per share computation	$ 72,609	$ 69,842	$ 50,813	$ 54,113	$ 70,981	$ 70,946	$ 53,821	$ 68,553	$ 247,377	$ 264,301	$ 225,291
Net earnings per share - basic	$ 0.49	$ 0.47	$ 0.34	$ 0.36	$ 0.47	$ 0.47	$ 0.36	$ 0.46	$ 1.67	$ 1.76	$ 1.46
Net earnings per share - diluted	$ 0.48	$ 0.46	$ 0.34	$ 0.36	$ 0.47	$ 0.46	$ 0.35	$ 0.45	$ 1.64	$ 1.73	$ 1.43