Derivative Financial Instruments and Hedging Activities (Details) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Derivative [Line Items]
Debt Carrying Value Fair Value	$ 39,733		$ 38,976
FMCC Fair Value	(360)		(21)
Income Effect of Derivative Financial Instruments [Abstract]
Derivative, Gain (Loss) on Derivative, Net	(71)	$ 102
Balance Sheet Effect of Derivative Financial Instruments [Abstract]
Notional	99,300		94,924
Fair Value of Derivative Assets	754		935
Fair Value of Derivative Liabilities	794		310
Derivative, Collateral, Obligation to Return Cash	22		15
Derivative, Collateral, Right to Reclaim Cash	55		38
Derivative Asset, Not Offset, Policy Election Deduction	231		162
FMCC Discontinued Hedging	66		77
Interest Rate Contract [Member] \| Not Designated as Hedging Instrument [Member]
Income Effect of Derivative Financial Instruments [Abstract]
Derivative, Gain (Loss) on Derivative, Net	(17)	7
Balance Sheet Effect of Derivative Financial Instruments [Abstract]
Notional	60,453		60,504
Interest Rate Contract [Member] \| Fair Value Hedging [Member] \| Designated as Hedging Instrument [Member]
Income Effect of Derivative Financial Instruments [Abstract]
Net interest settlements and accruals excluded from the assessment of hedge effectiveness	26	70
Change in Unrealized Gain (Loss) on Fair Value Hedging Instruments	(339)	(89)
Change in Unrealized Gain (Loss) on Hedged Item in Fair Value Hedge	329	85
Balance Sheet Effect of Derivative Financial Instruments [Abstract]
Notional	30,250		28,008
Foreign Exchange Contract [Member] \| Not Designated as Hedging Instrument [Member]
Income Effect of Derivative Financial Instruments [Abstract]
Derivative, Gain (Loss) on Derivative, Net	(12)	(29)
Balance Sheet Effect of Derivative Financial Instruments [Abstract]
Notional	2,885		2,406
Cross Currency Interest Rate Contract [Member] \| Not Designated as Hedging Instrument [Member]
Income Effect of Derivative Financial Instruments [Abstract]
Derivative, Gain (Loss) on Derivative, Net	(58)	$ 58
Balance Sheet Effect of Derivative Financial Instruments [Abstract]
Notional	5,712		4,006
Level 2 [Member] \| Fair Value, Measurements, Recurring [Member] \| Interest Rate Contract [Member] \| Not Designated as Hedging Instrument [Member]
Balance Sheet Effect of Derivative Financial Instruments [Abstract]
Fair Value of Derivative Assets	282		276
Fair Value of Derivative Liabilities	184		137
Level 2 [Member] \| Fair Value, Measurements, Recurring [Member] \| Interest Rate Contract [Member] \| Fair Value Hedging [Member] \| Designated as Hedging Instrument [Member]
Balance Sheet Effect of Derivative Financial Instruments [Abstract]
Fair Value of Derivative Assets	139		248
Fair Value of Derivative Liabilities	516		135
Level 2 [Member] \| Fair Value, Measurements, Recurring [Member] \| Foreign Exchange Contract [Member] \| Not Designated as Hedging Instrument [Member]
Balance Sheet Effect of Derivative Financial Instruments [Abstract]
Fair Value of Derivative Assets	28		3
Fair Value of Derivative Liabilities	34		10
Level 2 [Member] \| Fair Value, Measurements, Recurring [Member] \| Cross Currency Interest Rate Contract [Member] \| Not Designated as Hedging Instrument [Member]
Balance Sheet Effect of Derivative Financial Instruments [Abstract]
Fair Value of Derivative Assets	305		408
Fair Value of Derivative Liabilities	$ 60		$ 28

Balance Sheet Effect of Derivative Financial Instruments [Abstract]

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Fair value of hedged debt carried at cost which approximates fair value

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Aggregate fair value increase (decrease) to debt as of the balance sheet date related to previously designated hedging relationships that have been discontinued

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Aggregate fair value increase (decrease) to debt as of the balance sheet date related to designated fair value hedges of debt

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Income Effect of Derivative Financial Instruments [Abstract]

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Aggregate notional amount specified by the derivative(s). Expressed as an absolute value.

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-Publisher SEC
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Amount of gain (loss) from the increase (decrease) in fair value of derivative and nonderivative instruments designated as fair value hedging instruments recognized in the income statement.

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Amount of the increase (decrease) in fair value of the hedged item in a fair value hedge recognized in the income statement.

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Fair value of financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset, elected not to be offset, deducted from derivative assets.

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Amount of obligation to return cash collateral under master netting arrangements that have not been offset against derivative assets.

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Amount of right to receive cash collateral under master netting arrangements that have not been offset against derivative liabilities.

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Fair value, before effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets elected not to be offset. Excludes assets not subject to a master netting arrangement.

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Fair value, before effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes liabilities elected not to be offset. Excludes liabilities not subject to a master netting arrangement.

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Amount of increase (decrease) in the fair value of derivatives recognized in the income statement.

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The net gain (loss) included in earnings for the period relating to components of the gain (loss) on interest rate fair value hedging instruments excluded from the assessment of fair value hedge effectiveness.

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