Annual report pursuant to Section 13 and 15(d)

Leases - Additional Information (Detail)

v3.8.0.1
Leases - Additional Information (Detail) - USD ($)
$ in Millions
12 Months Ended
Aug. 31, 2017
Aug. 31, 2016
Aug. 31, 2015
Leases Disclosure [Line Items]      
Due in 2018 $ 28.0    
Due in 2019 22.9    
Due in 2020 18.6    
Due in 2021 13.3    
Due in 2022 10.7    
Due thereafter 12.7    
Operating lease, rental expense $ 37.4 $ 37.6 $ 35.7
Minimum      
Leases Disclosure [Line Items]      
Lease agreements period 1 year    
Maximum      
Leases Disclosure [Line Items]      
Lease agreements period 20 years