XML 108 R49.htm IDEA: XBRL DOCUMENT v2.4.0.6
Summary of Significant Accounting Policies (Details Textuals 1) (USD $)
 12 Months Ended
Jul. 31, 2012
Jul. 31, 2011
Jul. 31, 2010
Retained Insurance Liabilities [Abstract]      
Amount deductible per claim - insurance policies $ 250,000    
Amount deductible per claim - medical policy 225,000    
Self insured claims reserve 5,700,000 5,500,000  
Share-based Arrangements with Employees and Nonemployees [Abstract]      
Proceeds from the exercise of stock options 13,651,000 7,082,000 6,285,000
Excess tax benefit from stock-based payment compensation $ 4,367,000 $ 3,547,000 $ 5,643,000
Internally developed or purchased software
      
Property, Plant and Equipment [Line Items]      
Property and Equipment, estimated useful lives 3 to 5 years    
Transportation and other equipment
      
Property, Plant and Equipment [Line Items]      
Property and Equipment, estimated useful lives 3 to 7 years    
Office furniture and equipment
      
Property, Plant and Equipment [Line Items]      
Property and Equipment, estimated useful lives 3 to 10 years    
Buildings and leasehold improvements
      
Property, Plant and Equipment [Line Items]      
Property and Equipment, estimated useful lives 15 to 40 years or the lease term, whichever is shorter    
Leasehold improvements
      
Property, Plant and Equipment [Line Items]      
Property and Equipment, estimated useful lives between 5 and 10 years