XML 72 R61.htm IDEA: XBRL DOCUMENT v3.7.0.1
Indebtedness - Bank Debt - Additional Information (Detail) - Bank Credit Facility
3 Months Ended
Mar. 31, 2017
USD ($)
CommercialBank
Mar. 31, 2016
Mar. 21, 2017
USD ($)
Debt Instrument [Line Items]      
Bank Credit facility, maximum amount $ 4,000,000,000    
Bank Credit facility, borrowing base     $ 3,000,000,000
Bank commitments     $ 2,000,000,000
Percentage holding of commercial banks, Maximum 5.80%    
Number of commercial banks included in current bank group | CommercialBank 29    
Maturity date of loan Oct. 16, 2019    
Bank debt $ 846,000,000    
Undrawn letters of credit 279,700,000    
Borrowing capacity available under the commitment amount $ 874,300,000    
Weighted average interest rate on the bank credit facility 2.40% 2.10%  
Annual rate of commitment fee paid on the undrawn balance 0.30%    
Alternate Base Rate      
Debt Instrument [Line Items]      
Interest rate margin 0.50%    
LIBOR Rate      
Debt Instrument [Line Items]      
Interest rate margin 1.50%    
Minimum      
Debt Instrument [Line Items]      
Annual rate of commitment fee paid on the undrawn balance 0.30%    
Minimum | Credit Facility      
Debt Instrument [Line Items]      
Annual rate of commitment fee paid on the undrawn balance 0.15%    
Minimum | Alternate Base Rate      
Debt Instrument [Line Items]      
Base rate on debt 0.25%    
Minimum | Alternate Base Rate | Credit Facility      
Debt Instrument [Line Items]      
Base rate on debt 0.125%    
Minimum | LIBOR Rate      
Debt Instrument [Line Items]      
Base rate on debt 1.25%    
Minimum | LIBOR Rate | Credit Facility      
Debt Instrument [Line Items]      
Base rate on debt 1.125%    
Maximum      
Debt Instrument [Line Items]      
Annual rate of commitment fee paid on the undrawn balance 0.375%    
Maximum | Credit Facility      
Debt Instrument [Line Items]      
Annual rate of commitment fee paid on the undrawn balance 0.30%    
Maximum | Alternate Base Rate      
Debt Instrument [Line Items]      
Base rate on debt 1.25%    
Maximum | Alternate Base Rate | Credit Facility      
Debt Instrument [Line Items]      
Base rate on debt 0.75%    
Maximum | LIBOR Rate      
Debt Instrument [Line Items]      
Base rate on debt 2.25%    
Maximum | LIBOR Rate | Credit Facility      
Debt Instrument [Line Items]      
Base rate on debt 1.75%