Financial Instruments - Cross-Currency Swap Contract (Details) - Cross-currency swaps € in Millions, ¥ in Millions, $ in Millions	Jun. 30, 2020 EUR (€)	Jun. 30, 2020 USD ($)	Jun. 30, 2020 JPY (¥)	Dec. 31, 2019 EUR (€)	Dec. 31, 2019 USD ($)	Dec. 31, 2019 JPY (¥)
US dollar | Maturity July 2027
Derivative
Foreign currency notional amount		$ 1,100			$ 0
US dollar | Maturity March 2025
Derivative
Foreign currency notional amount		500			500
US dollar | Maturity February 2023
Derivative
Foreign currency notional amount		$ 100			$ 100
Euro | Maturity July 2027
Derivative
Foreign currency notional amount | €	€ 976			€ 0
Euro | Maturity March 2025
Derivative
Foreign currency notional amount | €	€ 450			€ 450
Japanese yen | Maturity February 2023
Derivative
Foreign currency notional amount | ¥			¥ 10,978			¥ 10,978