Summary of Significant Accounting Policies (Details Textuals 2) - USD ($) $ in Thousands	12 Months Ended
	Jul. 31, 2020	Jul. 31, 2019	Jul. 31, 2018
Property, Plant and Equipment [Line Items]
Software development costs, gross	$ 52,600	$ 39,400
Accumulated amortization	33,500	23,600
Share-based Payment Arrangement, Disclosure [Abstract]
Proceeds from the exercise of stock options	71,640	34,398	$ 44,459
Share-based Payment Arrangement, Expense, Tax Benefit	$ 92,500	$ 46,100	$ 21,300
Leasehold improvements
Property, Plant and Equipment [Line Items]
Description of useful lives	between seven and ten years
Internally developed or purchased software
Property, Plant and Equipment [Line Items]
Description of useful lives	three to seven years
Transportation and other equipment
Property, Plant and Equipment [Line Items]
Description of useful lives	three to twenty years
Office furniture and equipment
Property, Plant and Equipment [Line Items]
Description of useful lives	three to five years
Buildings and leasehold improvements
Property, Plant and Equipment [Line Items]
Description of useful lives	7 to 40 years or the lease term, whichever is shorter
Minimum | Leasehold improvements
Property, Plant and Equipment [Line Items]
Useful life (in years)	5 years
Minimum | Internally developed or purchased software
Property, Plant and Equipment [Line Items]
Useful life (in years)	3 years
Minimum | Transportation and other equipment
Property, Plant and Equipment [Line Items]
Useful life (in years)	3 years
Minimum | Office furniture and equipment
Property, Plant and Equipment [Line Items]
Useful life (in years)	3 years
Minimum | Buildings and leasehold improvements
Property, Plant and Equipment [Line Items]
Useful life (in years)	5 years
Maximum | Leasehold improvements
Property, Plant and Equipment [Line Items]
Useful life (in years)	10 years
Maximum | Internally developed or purchased software
Property, Plant and Equipment [Line Items]
Useful life (in years)	7 years
Maximum | Transportation and other equipment
Property, Plant and Equipment [Line Items]
Useful life (in years)	20 years
Maximum | Office furniture and equipment
Property, Plant and Equipment [Line Items]
Useful life (in years)	5 years
Maximum | Buildings and leasehold improvements
Property, Plant and Equipment [Line Items]
Useful life (in years)	40 years