Financial Instruments, Hedging Activities and Fair Value Measurements (Additional Information) (Details) $ in Millions, € in Billions	3 Months Ended	12 Months Ended
	Mar. 31, 2020 EUR (€)	Dec. 31, 2019 EUR (€)	Mar. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)	Mar. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)
Derivative Instruments and Hedging Activities Disclosure [Line Items]
Foreign Currency Contract, Asset, Fair Value Disclosure			$ 3
Foreign Currency Contracts, Liability, Fair Value Disclosure				$ 1
Derivative Instruments in Hedges, Net Investment in Foreign Operations, Assets, Fair Value, Net			90	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			4,837	5,403	$ 5,010	$ 4,732
Long-term Debt			5,246	5,031
Long-lived assets fair value amount			5,443	5,363
Total lease obligations			9
Short-term debt			952	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			76	35
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			3,400	2,800
Foreign Currency Contracts, Liability, Fair Value Disclosure			14	6
Cash Flow Hedging
Derivative Instruments and Hedging Activities Disclosure [Line Items]
Derivative, Notional Amount			18	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			$ 313	$ 235