Annual report pursuant to Section 13 and 15(d)

Commitments and Contingencies - Additional Information (Detail)

v3.8.0.1
Commitments and Contingencies - Additional Information (Detail) - USD ($)
$ in Millions
Aug. 31, 2017
Aug. 31, 2016
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]    
Outstanding letters of credit $ 14.5 $ 17.8
Discounted present value of future minimum lease payments $ 13.5  
Weighted Average Discount Rate on Future Minimum Lease Payments 2.29%  
Electrical    
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]    
Discounted present value of future minimum lease payments $ 10.7