Employee Benefit Plans - Schedule of Assumptions Used (Details)	12 Months Ended
	Jul. 31, 2013 Rate	Jul. 31, 2012 Rate	Jul. 31, 2011
Compensation and Retirement Disclosure [Abstract]
Weighted average discount rate used in determining accumulated postretirement benefit obligation liability	4.00%	3.25%	4.50%
Weighted average discount rate used in determining net periodic benefit cost	3.25%	4.50%	4.50%
Assumed health care trend rate used to measure APBO at July 31	8.00%	8.00%	0.00%
Rate to which cost trend rate is assumed to decline (the ultimate trend rate)	5.50%	5.50%	5.50%
Fiscal year the ultimate trend rate is reached	2017	2016	2017