Quarterly report pursuant to Section 13 or 15(d)

Description of Business, Basis of Presentation, and Significant Accounting Policies (Details)

v3.5.0.2
Description of Business, Basis of Presentation, and Significant Accounting Policies (Details)
$ / shares in Units, $ in Millions
 3 Months Ended 12 Months Ended
Aug. 31, 2016
USD ($)
segment
$ / shares
Aug. 31, 2015
USD ($)
May 31, 2016
USD ($)
Accounting Policies [Line Items]      
State of incorporation Delaware    
Number of reportable segments | segment 1    
Allowance for doubtful accounts $ 4.7   $ 4.2
Accounts receivable, net of allowance for doubtful accounts 485.6   408.6
Maximum individual workers' compensation claims liability 1.3   1.3
Maximum individual health insurance claims liability 0.3   0.3
Stock-based compensation costs recognized 9.1 $ 8.8  
Excess tax benefit in income tax expense $ 13.2    
Diluted earnings per share increase | $ / shares $ 0.035    
Trade Receivables [Member]      
Accounting Policies [Line Items]      
Accounts receivable, net of allowance for doubtful accounts $ 280.2   221.6
Purchased Receivables [Member]      
Accounting Policies [Line Items]      
Accounts receivable, net of allowance for doubtful accounts $ 205.4   $ 187.0
Germany [Member] | Total Revenue [Member] | Geographic Concentration Risk [Member]      
Accounting Policies [Line Items]      
Percentage of total revenue less than one percent 1.00% 1.00%