Consolidated Statements Of Changes In Shareholders' Equity (Parenthetical) (USD $)	3 Months Ended						12 Months Ended
	Jul. 31, 2012	Apr. 30, 2012	Jan. 31, 2012	Oct. 31, 2011	Jul. 31, 2011	Jan. 31, 2011	Jul. 31, 2012	Jul. 31, 2011	Jul. 31, 2010
Consolidated Statements Of Changes In Shareholders' Equity [Abstract]
Dividends, per share	$ 0.090	$ 0.090	$ 0.080	$ 0.075	$ 0.150	$ 0.130	$ 0.335	$ 0.28	$ 0.24