Employee Benefit Plans (Components Of Net Periodic Pension Costs) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Oct. 31, 2011	Oct. 31, 2010
Employee Benefit Plans [Abstract]
Service cost	$ 3,898	$ 3,972
Interest cost	4,893	4,810
Expected return on assets	(7,053)	(6,840)
Transition amount amortization	57	54
Prior service cost amortization	128	116
Actuarial loss amortization	1,443	810
Net periodic benefit cost	$ 3,366	$ 2,922