Financial Instruments, Hedging Activities and Fair Value Measurements (Additional Information) (Details) $ in Millions, € in Billions	6 Months Ended	9 Months Ended
	Jun. 30, 2020 EUR (€)	Sep. 30, 2020 EUR (€)	Sep. 30, 2020 USD ($)	Jun. 30, 2020 USD ($)	Mar. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)	Sep. 30, 2019 USD ($)	Jun. 30, 2019 USD ($)	Mar. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)
Derivative Instruments and Hedging Activities Disclosure [Line Items]
Foreign Currency Contracts, Liability, Fair Value Disclosure						$ 1
Derivative Instruments in Hedges, Net Investment in Foreign Operations, Assets, Fair Value, Net			$ 34			48
Fair Value of Debt Instrument Designated as a Hedge of Net Investment in Foreign Operations			2,300			2,200
Accumulated pretax unrealized translation gains (losses) in AOCI, related to both the euro-denominated borrowings and the cross currency swaps that have been designated as hedges of net investments			5,424	$ 4,938	$ 4,837	5,403	$ 5,355	$ 5,187	$ 5,010	$ 4,732
Long-term Debt			4,954			5,031
Long-lived assets fair value amount			5,520			5,363
Finance Lease, Liability			9
Short-term debt			540			10
Capital Lease Obligations						11
Interest rate swaps
Derivative Instruments and Hedging Activities Disclosure [Line Items]
Derivative, Notional Amount			525
Interest Rate Derivatives, at Fair Value, Net						35	$ 74
Cross currency swaps
Derivative Instruments and Hedging Activities Disclosure [Line Items]
Derivative, Notional Amount			875			875
Foreign currency forward contracts
Derivative Instruments and Hedging Activities Disclosure [Line Items]
Derivative, Notional Amount			1,100			2,800
Foreign Currency Contracts, Liability, Fair Value Disclosure			3			6
Foreign currency forward contracts | Accounts payable and accrued liabilities | Level 1
Derivative Instruments and Hedging Activities Disclosure [Line Items]
Derivative liabilities			0			0
Foreign currency forward contracts | Accounts payable and accrued liabilities | Level 1 | Not Designated as Hedging Instrument
Derivative Instruments and Hedging Activities Disclosure [Line Items]
Derivative liabilities			0			0
Foreign currency forward contracts | Accounts payable and accrued liabilities | Level 2
Derivative Instruments and Hedging Activities Disclosure [Line Items]
Derivative liabilities			0			1
Foreign currency forward contracts | Accounts payable and accrued liabilities | Level 2 | Not Designated as Hedging Instrument
Derivative Instruments and Hedging Activities Disclosure [Line Items]
Derivative liabilities			12			20
Foreign currency forward contracts | Accounts payable and accrued liabilities | Level 3
Derivative Instruments and Hedging Activities Disclosure [Line Items]
Derivative liabilities			0			0
Foreign currency forward contracts | Accounts payable and accrued liabilities | Level 3 | Not Designated as Hedging Instrument
Derivative Instruments and Hedging Activities Disclosure [Line Items]
Derivative liabilities			0			0
Cash Flow Hedging
Derivative Instruments and Hedging Activities Disclosure [Line Items]
Derivative, Notional Amount						43
Net Investment Hedging
Derivative Instruments and Hedging Activities Disclosure [Line Items]
Long-term Debt | €	€ 2.0	€ 2.0
Accumulated Gain (Loss), Cash Flow Hedge, Including Noncontrolling Interest
Derivative Instruments and Hedging Activities Disclosure [Line Items]
Accumulated pretax unrealized translation gains (losses) in AOCI, related to both the euro-denominated borrowings and the cross currency swaps that have been designated as hedges of net investments			$ 120			$ 235