Financial Instruments (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Financial Instruments and Fair Value [Line Items]
Gross realized gains on the sale of our marketable securities	$ 292	$ 1,300	$ 185
Gross realized losses on the sale of our marketable securities	143	143	295
Other-than-temporary impairment losses	0	0	$ 0
Fair value of non-marketable equity securities	11,353	12,275
Equity method investments	1,300	1,300
Cash collateral received from derivative financial instruments	252	327
Foreign currency gain (loss) to be reclassified during next 12 months	82
Cash Flow Hedging Relationship \| Foreign exchange contracts
Financial Instruments and Fair Value [Line Items]
Notional principal	$ 13,200	11,800
Foreign exchange option contracts, maximum maturities	24 months
Derivatives in Fair Value Hedging Relationship \| Foreign exchange contracts
Financial Instruments and Fair Value [Line Items]
Notional principal	$ 455	2,000
Net Investment Hedges \| Foreign exchange contracts
Financial Instruments and Fair Value [Line Items]
Notional principal	9,300	6,700
Fair Value of Derivatives Not Designated as Hedging Instruments \| Foreign exchange contracts
Financial Instruments and Fair Value [Line Items]
Notional principal	43,500	$ 20,100
Valuation, Market Approach
Financial Instruments and Fair Value [Line Items]
Fair value of non-marketable equity securities	7,600
Unrealized gain on equity securities	$ 1,800

Cash collateral received from derivative financial instruments.

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Financial Instruments and Fair Value [Line Items]

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Amount of realized gain on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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-Publisher FASB
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Amount of realized loss on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Nominal or face amount used to calculate payment on derivative.

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Period remaining until the derivative contract matures, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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This item represents the carrying amount on the entity's balance sheet of its investment in common stock of an equity method investee. This is not an indicator of the fair value of the investment, rather it is the initial cost adjusted for the entity's share of earnings and losses of the investee, adjusted for any distributions (dividends) and other than temporary impairment (OTTI) losses recognized.

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Amount of investment in equity security without readily determinable fair value.

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Amount of cumulative gain from upward price adjustment on investment in equity security without readily determinable fair value.

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The estimated net amount of unrealized gains or losses on foreign currency cash flow hedges at the reporting date expected to be reclassified to earnings within the next 12 months.

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The amount by which the fair value of an investment is less than the amortized cost basis or carrying amount of that investment at the balance sheet date and the decline in fair value is deemed to be other than temporary, before considering whether or not such amount is recognized in earnings or other comprehensive income.

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