Employee Benefit Plans (Components Of Net Periodic Pension Costs) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jan. 31, 2012	Jan. 31, 2011	Jan. 31, 2012	Jan. 31, 2011
Employee Benefit Plans [Abstract]
Service cost	$ 3,862	$ 4,102	$ 7,760	$ 8,074
Interest cost	4,848	4,851	9,741	9,661
Expected return on assets	(7,005)	(6,856)	(14,058)	(13,696)
Transition amount amortization	54	55	111	109
Prior service cost amortization	127	112	255	228
Actuarial loss amortization	1,438	842	2,881	1,652
Net periodic benefit cost	$ 3,324	$ 3,106	$ 6,690	$ 6,028