Derivative Instruments and Hedging Activities (Schedule of Fair Value Hedging Instruments, Statements of Financial Performance and Financial Position, Location) (Details) - USD ($) $ in Millions	Mar. 31, 2019	Dec. 31, 2018
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Long-term debt	$ 41,490	$ 44,193
Amortized cost basis of the closed portfolios used in hedging relationships	46	47
Hedged asset, last-of-layer, amount	9,600	21,400
Hedged liability, fair value hedge, cumulative increase (decrease)	5
Hedge basis adjustment, last-of-layer		19
Hedged asset, discontinued fair value hedge, last-of-layer amount	11,200
Carrying amount
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Available-for-sale debt securities	1,495	1,485
Finance receivables and loans, net	36,433	40,850
Long-term debt	12,263	13,001
Available-for-sale securities
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Cumulative basis adjustments for fair value hedges included in the carrying amount of hedged items	(10)	0
Hedged asset, last-of-layer, amount	28	28
Hedged asset, discontinued fair value hedge, cumulative increase (decrease)	0	0
Available-for-sale securities \| Discontinued hedge
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Cumulative basis adjustments for fair value hedges included in the carrying amount of hedged items	(8)	5
Finance receivables and loans, net
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Cumulative basis adjustments for fair value hedges included in the carrying amount of hedged items	(63)	(24)
Hedged asset, discontinued fair value hedge, cumulative increase (decrease)	65
Finance receivables and loans, net \| Discontinued hedge
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Cumulative basis adjustments for fair value hedges included in the carrying amount of hedged items	(68)	(5)
Long-term debt
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Hedged liability, fair value hedge, cumulative increase (decrease)	66	67
Long-term debt \| Discontinued hedge
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Hedged liability, fair value hedge, cumulative increase (decrease)	$ 66	$ 67

Hedged Asset, Discontinued Fair Value Hedge, Last-of-Layer, Amount

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Amount of 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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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Amount of cumulative increase (decrease) in fair value of hedged asset in fair value hedge, attributable to hedged risk, remaining after discontinued hedge.

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Amount of cumulative increase (decrease) in fair value of hedged asset in fair value hedge, attributable to hedged risk.

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Amount of asset hedged in last of layer, expected to be remaining at end of hedging relationship.

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Amount of cumulative increase (decrease) in fair value of hedged asset in fair value hedge, attributable to hedged risk, in last-of-layer hedging relationship.

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Amount of cumulative increase (decrease) in fair value of hedged liability in fair value hedge, attributable to hedged risk.

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Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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Net amount of the investment in a contractual right to receive money on demand or on fixed or determinable dates that is recognized as an asset in the creditor's statement of financial position. Examples include, but are not limited to, credit card receivables, notes receivable and receivables relating to lessor's rights to payments from leases other than operating leases that have been recorded as assets. Excludes trade accounts receivable with contractual maturity of one year or less and arose from the sale of goods or services.

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Amortized cost of closed portfolio of prepayable financial asset, used to designate hedging relationship in which hedged item is last layer expected to be remaining at end of hedging relationship.

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