v3.20.2
Revenue Recognition (Deferred Contract Acquisition and Fulfillment Costs) (Details) - USD ($)
$ in Millions
 6 Months Ended
Jun. 30, 2020
Jun. 30, 2019
Dec. 31, 2019
Deferred Customer Contract Acquisition Costs [Member]      
Capitalized Contract Cost, Net [Abstract]      
Capitalized Contract Cost, Net (in millions) $ 5,747   $ 5,453
Capitalized Contract Cost, Amortization (in millions) 1,278 $ 1,026  
Deferred Customer Contract Acquisition Costs [Member] | Other Current Assets [Member]      
Capitalized Contract Cost, Net [Abstract]      
Capitalized Contract Cost, Net (in millions) 2,630   2,462
Deferred Customer Contract Acquisition Costs [Member] | Other Assets [Member]      
Capitalized Contract Cost, Net [Abstract]      
Capitalized Contract Cost, Net (in millions) 3,117   2,991
Deferred Customer Contract Fulfillment Cost [Member]      
Capitalized Contract Cost, Net [Abstract]      
Capitalized Contract Cost, Net (in millions) 10,342   10,958
Capitalized Contract Cost, Amortization (in millions) 2,636 $ 2,381  
Deferred Customer Contract Fulfillment Cost [Member] | Other Current Assets [Member]      
Capitalized Contract Cost, Net [Abstract]      
Capitalized Contract Cost, Net (in millions) 4,362   4,519
Deferred Customer Contract Fulfillment Cost [Member] | Other Assets [Member]      
Capitalized Contract Cost, Net [Abstract]      
Capitalized Contract Cost, Net (in millions) $ 5,980   $ 6,439