v3.8.0.1
DEBT (Details) - USD ($)
Sep. 25, 2017
Sep. 06, 2017
Sep. 30, 2018
Sep. 30, 2017
Sep. 12, 2017
Dec. 31, 2016
Jun. 17, 2014
Debt              
Debt instrument unused and available borrowing capacity amount       $ 4,740,000,000      
Maximum borrowing capacity       5,015,000,000      
Carrying Value              
Debt              
Long-term debt, including current portion       4,533,000,000   $ 4,007,000,000  
Fair value | Level 2              
Debt              
Long-term debt, including current portion       4,714,000,000   $ 4,163,000,000  
Loders | Scenario, Forecast              
Debt              
Interest acquired (as a percent)     70.00%        
Unsecured Debt | $900 Million Unsecured Term Loan              
Debt              
Principle amount         $ 900,000,000    
Long-term debt $ 0            
Senior Notes | 3.00% Unsecured Senior Notes and 3.75% Unsecured Senior Notes              
Debt              
Net proceeds from issuance of debt 989,000,000            
Senior Notes | 3.00% Unsecured Senior Notes              
Debt              
Principle amount $ 400,000,000            
Stated interest rate (as a percent) 3.00%            
Senior Notes | 3.75% Unsecured Senior Notes              
Debt              
Principle amount $ 600,000,000            
Stated interest rate (as a percent) 3.75%            
Commercial paper program              
Debt              
Commercial paper, outstanding issuances       0      
Liquidity facility              
Debt              
Credit facility, borrowings outstanding       0      
Line of Credit | Credit Agreement              
Debt              
Credit facility, borrowings outstanding       $ 75,000,000      
Principle amount             $ 865,000,000
Line of Credit | Credit Agreement | Minimum              
Debt              
Commitment fee   0.125%          
Line of Credit | Credit Agreement | Maximum              
Debt              
Commitment fee   0.275%          
Line of Credit | Credit Agreement | LIBOR | Minimum              
Debt              
Variable interest rate   1.00%          
Line of Credit | Credit Agreement | LIBOR | Maximum              
Debt              
Variable interest rate   1.75%