XML 30 R96.htm IDEA: XBRL DOCUMENT v3.19.3.a.u2
Financing arrangements (Shelf Registration Statements and Other Facilities) (Details) - Line of credit [Member]
12 Months Ended
Dec. 31, 2019
USD ($)
renewal_option
Dec. 31, 2018
USD ($)
Dec. 31, 2014
USD ($)
Debt Instrument [Line Items]      
Maximum current borrowing capacity under a syndicated, unsecured, revolving credit agreement     $ 2,500,000,000
Amount by which borrowing capacity under a syndicated unsecured revolving credit agreement may be increased upon our request at discretion of banks $ 750,000,000    
Initial commitment term of each bank which is a party to the agreement 5 years    
Number of additional term extension options | renewal_option 2    
Additional period for extension of commitment term 1 year    
Annual commitment fees for syndicated, unsecured, revolving credit agreement 0.09%    
Basis spread on variable rate 1.00%    
Amount outstanding under syndicated, unsecured, revolving credit facility $ 0 $ 0  
Fed Funds Effective Rate Overnight Index Swap Rate [Member]      
Debt Instrument [Line Items]      
Basis spread on variable rate 0.50%    
LIBOR [Member]      
Debt Instrument [Line Items]      
Basis spread on variable rate 1.00%    
Description of variable rate basis one-month LIBOR