Retirement and Profit Sharing Plans (Details) $ in Millions	12 Months Ended
	Jul. 31, 2016 USD ($) hour	Jul. 31, 2015 USD ($)	Jul. 31, 2014 USD ($)
Compensation and Retirement Disclosure [Abstract]
Employee contribution percentage	100.00%
Company match amount equal to participant's contribution	50.00%
Employer contribution matching equal to 50%	6.00%
Employment period (in months)	12 months
Service period (in hours)	1,000
Total service period (in hours)	1,500
Retirement plan expense | $	$ 5.3	$ 4.5	$ 4.1