v3.20.2
Derivative and Financial Instruments - Financial Instruments at fair value (Details) - USD ($)
$ in Millions
Sep. 30, 2020
Dec. 31, 2019
Schedule Of Available For Sale Securities [Line Items]    
Cash and cash equivalents $ 2,490 $ 5,088
Short-term Investments 4,032 3,028
Investments and long-term receiavables 8,295 8,687
Carrying (Reported) Amount, Fair Value Disclosure [Member]    
Schedule Of Available For Sale Securities [Line Items]    
Cash and cash equivalents 3 9
Short-term Investments 273 99
Investments and long-term receiavables 206 133
Corporate Bonds [Member] | Remaining maturities within one year [Member] | Carrying (Reported) Amount, Fair Value Disclosure [Member]    
Schedule Of Available For Sale Securities [Line Items]    
Cash and cash equivalents 0 1
Short-term Investments 157 59
Investments and long-term receiavables 0 0
Corporate Bonds [Member] | Remaining Maturities Greater Than One Year Through Five Years [Member] | Carrying (Reported) Amount, Fair Value Disclosure [Member]    
Schedule Of Available For Sale Securities [Line Items]    
Cash and cash equivalents 0 0
Short-term Investments 0 0
Investments and long-term receiavables 128 99
Commercial Paper [Member] | Remaining maturities within one year [Member] | Carrying (Reported) Amount, Fair Value Disclosure [Member]    
Schedule Of Available For Sale Securities [Line Items]    
Cash and cash equivalents 3 8
Short-term Investments 108 30
Investments and long-term receiavables 0 0
Government obligations [Member] | Remaining maturities within one year [Member] | Carrying (Reported) Amount, Fair Value Disclosure [Member]    
Schedule Of Available For Sale Securities [Line Items]    
Cash and cash equivalents 0 0
Short-term Investments 8 10
Investments and long-term receiavables 0 0
Government obligations [Member] | Remaining Maturities Greater Than One Year Through Five Years [Member] | Carrying (Reported) Amount, Fair Value Disclosure [Member]    
Schedule Of Available For Sale Securities [Line Items]    
Cash and cash equivalents 0 0
Short-term Investments 0 0
Investments and long-term receiavables 13 15
U.S. Government Agency Obligations [Member] | Remaining Maturities Greater Than One Year Through Five Years [Member] | Carrying (Reported) Amount, Fair Value Disclosure [Member]    
Schedule Of Available For Sale Securities [Line Items]    
Cash and cash equivalents 0 0
Short-term Investments 0 0
Investments and long-term receiavables 17 0
Foreign government obligations [Member] | Remaining Maturities Greater Than One Year Through Five Years [Member] | Carrying (Reported) Amount, Fair Value Disclosure [Member]    
Schedule Of Available For Sale Securities [Line Items]    
Cash and cash equivalents 0 0
Short-term Investments 0 0
Investments and long-term receiavables 2 0
Asset-backed Securities [Member] | Remaining Maturities Greater Than One Year Through Five Years [Member] | Carrying (Reported) Amount, Fair Value Disclosure [Member]    
Schedule Of Available For Sale Securities [Line Items]    
Cash and cash equivalents 0 0
Short-term Investments 0 0
Investments and long-term receiavables $ 46 $ 19