XML 92 R79.htm IDEA: XBRL DOCUMENT v3.8.0.1
Debt Obligations - Credit Facility - Current Borrowings (Detail) - USD ($)
$ in Thousands
Dec. 31, 2017
Dec. 31, 2016
Line of Credit Facility [Line Items]    
Amount borrowed under the credit facility $ 668,427 $ 351,341
Credit facility available for revolving loans or issuing new letters of credit 728,300  
Letters Of Credit and Bank Guarantees    
Line of Credit Facility [Line Items]    
Letters of credit and bank guarantees under the credit facility 413,300  
Letters Of Credit and Bank Guarantees | U S Dollar    
Line of Credit Facility [Line Items]    
Letters of credit and bank guarantees under the credit facility 228,600  
Letters Of Credit and Bank Guarantees | Primarily Canadian and Australian dollars    
Line of Credit Facility [Line Items]    
Letters of credit and bank guarantees under the credit facility 184,700  
Borrowings Under Credit Facility    
Line of Credit Facility [Line Items]    
Amount borrowed under the credit facility 668,400  
Borrowings Under Credit Facility | U S Dollar    
Line of Credit Facility [Line Items]    
Amount borrowed under the credit facility 645,000  
Borrowings Under Credit Facility | Australian Dollars    
Line of Credit Facility [Line Items]    
Amount borrowed under the credit facility $ 23,400