XML 164 R108.htm IDEA: XBRL DOCUMENT v3.8.0.1
Capital Disclosures (Details) - USD ($)
 12 Months Ended
Dec. 31, 2017
Feb. 28, 2017
Dec. 31, 2016
Dec. 31, 2015
Disclosure of detailed information about borrowings [line items]        
Available borrowings $ 73,500,000   $ 70,000,000  
Former Revolving Facility        
Disclosure of detailed information about borrowings [line items]        
Line of credit, maximum borrowing capacity       $ 300,000,000
Revolving Facility        
Disclosure of detailed information about borrowings [line items]        
Line of credit, maximum borrowing capacity 300,000,000      
Amount of accordion feature 150,000,000.0      
Borrowings 0   15,000,000  
Available borrowings 276,800,000      
Credit Facility        
Disclosure of detailed information about borrowings [line items]        
Borrowings 187,500,000   227,500,000  
Letters of credit outstanding 23,200,000   25,800,000  
Bridge Loan | Revolving Facility        
Disclosure of detailed information about borrowings [line items]        
Line of credit, maximum borrowing capacity $ 25,000,000.0      
Bridge Loan | Revolving Facility | Top of range        
Disclosure of detailed information about borrowings [line items]        
Debt instrument term 7 days      
Factoring of receivables from facility program        
Disclosure of detailed information about borrowings [line items]        
Agreement to sell trade receivables, maximum capacity $ 200,000,000 $ 250,000,000.0    
Accounts receivable sold during period $ 80,000,000   50,000,000  
Term of agreement extensions 1 year      
Factoring of receivables from supplier financing program        
Disclosure of detailed information about borrowings [line items]        
Accounts receivable sold during period $ 52,300,000   $ 51,400,000