Commitments and Contingencies (Details Textuals) - USD ($) $ in Millions					12 Months Ended
	Aug. 04, 2015	Jun. 22, 2015	Jun. 05, 2015	Jun. 30, 2011	Jul. 31, 2016	Jul. 31, 2015	Jul. 31, 2014
Major Operating and Capital Expenses [Abstract]
Outstanding letter of credit					$ 15.3
Facilities Rental Expense
Major Operating and Capital Expenses [Abstract]
Rental expense					21.6	$ 21.7	$ 26.4
Yard Operations Equipment Rental Expense
Major Operating and Capital Expenses [Abstract]
Rental expense					$ 3.1	$ 3.6	$ 3.0
Georgia Department of Revenue | Insurance-related Assessments
Major Operating and Capital Expenses [Abstract]
Sales tax liability contingency	$ 96.1	$ 100.0	$ 2.7	$ 73.8