v3.20.4
Contingencies and Certain Commitments (Certain Commitments and Contingent Consideration for Acquisitions) (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Commitments and Contingencies Disclosure [Abstract]    
Long-term purchase commitment, amount $ 3,800  
Fair value of contingent consideration 689 $ 711
Contingent consideration liability, current 123 160
Contingent consideration liability, noncurrent $ 566 $ 551