XML 64 R51.htm IDEA: XBRL DOCUMENT v3.8.0.1
Long-Term Debt (Details of the Company's Credit Agreement) (Details) - USD ($)
$ in Thousands
9 Months Ended 12 Months Ended
Sep. 30, 2017
Dec. 31, 2016
Line of Credit Facility [Line Items]    
Amount drawn $ 3,953,167 $ 3,632,692
Revolving Credit Facility [Member] | Credit Agreement [Member]    
Line of Credit Facility [Line Items]    
Available $ 1,122,149 $ 1,004,451
Commitment - rate applicable 0.15% 0.15%
Amount drawn [1] $ 218,755 $ 310,582
Letter of Credit [Member] | Credit Agreement [Member]    
Line of Credit Facility [Line Items]    
Letter of credit 221,596 247,467
LIBOR [Member] | Term Loan Facility [Member] | Credit Agreement [Member]    
Line of Credit Facility [Line Items]    
Amount drawn $ 1,637,500 $ 1,637,500
Interest rate applicable 2.44% 1.97%
Canadian Prime Rate [Member] | Revolving Credit Facility [Member] | Credit Agreement [Member]    
Line of Credit Facility [Line Items]    
Amount drawn $ 12,020 $ 7,448
Interest rate applicable 3.45% 2.95%
Canadian Bankers Acceptance Loan [Member] | Revolving Credit Facility [Member] | Credit Agreement [Member]    
Line of Credit Facility [Line Items]    
Amount drawn $ 206,735 $ 303,134
Interest rate applicable 2.51% 2.13%
[1] Interest rates represent the interest rates incurred at September 30, 2017