Annual report pursuant to Section 13 and 15(d)

Acquisitions - Additional Information (Detail)

v3.8.0.1
Acquisitions - Additional Information (Detail)
$ in Thousands
 12 Months Ended
Aug. 31, 2017
USD ($)
Mar. 31, 2016
USD ($)
Feb. 18, 2016
USD ($)
Aug. 31, 2017
USD ($)
acquisition
Aug. 31, 2016
USD ($)
acquisition
Aug. 31, 2015
USD ($)
acquisition
Mar. 30, 2016
USD ($)
Feb. 17, 2016
USD ($)
Business Acquisition [Line Items]                
Cash paid for business acquisitions, net of cash acquired       $ 0 $ 81,916 $ 0    
Recognition of Goodwill due to Business acquired         $ 45,967      
Number of businesses acquired | acquisition       0 2 0    
Goodwill, Purchase Accounting Adjustments       $ 1,085        
Net sales       1,095,784 $ 1,149,410 $ 1,249,254    
Mirage Machines [Domain]                
Business Acquisition [Line Items]                
Definitive Agreement Purchase Price $ 16,000              
Larzep                
Business Acquisition [Line Items]                
Business Acquisition, Date of Acquisition Agreement     Feb. 17, 2016          
Cash paid for business acquisitions, net of cash acquired     $ 15,900          
Recognition of Goodwill due to Business acquired     $ 9,700          
Recognition of Intangible Assets Acquired               $ 4,800
Pipeline and Process Services                
Business Acquisition [Line Items]                
Business Acquisition, Date of Acquisition Agreement   Mar. 30, 2016            
Cash paid for business acquisitions, net of cash acquired   $ 65,500            
Recognition of Goodwill due to Business acquired   37,400            
Recognition of Intangible Assets Acquired             $ 8,700  
Goodwill, Purchase Accounting Adjustments   $ 1,100            
Fiscal 2016 acquisitions [Member]                
Business Acquisition [Line Items]                
Net sales       $ 32,800 19,100      
Acquisition Costs, Period Cost         $ 2,100      
Customer Relationships | Larzep                
Business Acquisition [Line Items]                
Recognition of Intangible Assets Acquired               3,600
Customer Relationships | Pipeline and Process Services                
Business Acquisition [Line Items]                
Recognition of Intangible Assets Acquired             8,000  
Non-compete Agreements | Pipeline and Process Services                
Business Acquisition [Line Items]                
Recognition of Intangible Assets Acquired             $ 700  
Trade Names | Larzep                
Business Acquisition [Line Items]                
Recognition of Intangible Assets Acquired               $ 1,200