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Financial Instruments - Narrative (Details)	3 Months Ended
	Mar. 31, 2020 USD ($) interest_rate_swap	Dec. 31, 2019 USD ($)	Mar. 31, 2019 USD ($)	Feb. 29, 2020 USD ($)
Derivative [Line Items]
Pretax net unrealized gain on derivatives maturing within next 12 months estimated to be reclassified from AOCI to sales	$ 136,000,000
Equity investments without readily determinable fair values	450,000,000		$ 542,000,000
Unrealized losses recognized on investments in equity securities without readily determinable fair values			9,000,000
Cumulative unrealized gains on investments	109,000,000
Cumulative unrealized losses on investments	21,000,000
Payments of contingent consideration	106,000,000		$ 85,000,000
Fair value of loans payable and long-term debt, including current portion	30,600,000,000	$ 28,800,000,000
Debt, carrying amount	28,000,000,000.0	26,300,000,000
Accounts Receivable, Sale	1,900,000,000	2,700,000,000
Cash collateral received from counterparties	216,000,000	34,000,000
Cash collateral advanced to counterparties	0	0
Total swap notional amount	27,453,000,000	30,666,000,000
Level 2
Derivative [Line Items]
Cash equivalents	6,800,000,000	8,900,000,000
Derivatives Designated as Hedging Instruments
Derivative [Line Items]
Total swap notional amount	$ 12,749,000,000	14,728,000,000
Derivatives Designated as Hedging Instruments | Maximum
Derivative [Line Items]
Maximum average period of maturities of contracts in years (less than)	2 years
Derivatives Not Designated as Hedging Instruments
Derivative [Line Items]
Total swap notional amount	$ 14,704,000,000	$ 15,938,000,000
Derivatives Not Designated as Hedging Instruments | Maximum
Derivative [Line Items]
Maximum average period of maturities of contracts in years (less than)	1 year
1.85% Notes Due 2020
Derivative [Line Items]
Face amount of debt				$ 1,250,000,000
Stated interest rate (as percent)				1.85%
Interest rate swap contracts
Derivative [Line Items]
Number of interest rate swaps held (in interest rate swaps)	14			5
Total swap notional amount				$ 250,000,000

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