Financial Instruments, Hedging Activities and Fair Value Measurements (Additional Information) (Details) $ in Millions, € in Billions	3 Months Ended	6 Months Ended
	Mar. 31, 2020 EUR (€)	Jun. 30, 2020 EUR (€)	Jun. 30, 2020 USD ($)	Mar. 31, 2020 USD ($)	Dec. 31, 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			$ 73		48
Fair Value of Debt Instrument Designated as a Hedge of Net Investment in Foreign Operations			2,200		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			4,938	$ 4,837	5,403	$ 5,187	$ 5,010	$ 4,732
Long-term Debt			4,776		5,031
Long-lived assets fair value amount			5,221		5,363
Finance Lease, Liability			8
Short-term debt			1,500		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	$ 78
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			1,300		2,800
Foreign Currency Contracts, Liability, Fair Value Disclosure			7		6
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			$ 256		$ 235