Finance Receivables - Aging Analysis (Details) - USD ($) $ in Millions	9 Months Ended
Sep. 30, 2019	Dec. 31, 2018	Sep. 30, 2018
Accounts, Notes, Loans and Financing Receivable [Line Items]
Threshold Period For Past Due Finance Receivables	31 days
Finance Receivables Aging Analysis [Abstract]
Financing Receivables	$ 113,284	$ 119,403	$ 116,630
Uncollected Interest Receivable Excluded From Finance Receivable	241	264
Consumer Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing	0	20
Finance Receivables Aging Analysis [Abstract]
Total past due	928	1,060
Current	72,970	75,179
Financing Receivables	73,898	76,239	76,827
Non-Consumer Segment [Member]
Finance Receivables Aging Analysis [Abstract]
Total past due	70	76
Current	39,316	43,088
Financing Receivables	39,386	43,164	$ 39,803
31-60 Days Past Due [Member] \| Consumer Segment [Member]
Finance Receivables Aging Analysis [Abstract]
Total past due	741	859
61-90 Days Past Due [Member] \| Consumer Segment [Member]
Finance Receivables Aging Analysis [Abstract]
Total past due	110	123
91-120 Days Past Due [Member] \| Consumer Segment [Member]
Finance Receivables Aging Analysis [Abstract]
Total past due	39	39
Greater Than 120 Days Past Due [Member] \| Consumer Segment [Member]
Finance Receivables Aging Analysis [Abstract]
Total past due	$ 38	$ 39

Finance Receivables Aging Analysis [Abstract]

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Threshold Period For Past Due Finance Receivables

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The amount of uncollected interest receivable excluded from finance receivable.

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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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Recorded investment in financing receivables that are 90 days or more past due and still accruing.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 7
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Financing receivables that are current.

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
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-URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953401-111524

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Recorded Investment in financing receivables that are past due at the balance sheet date.

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Amount representing an agreement for an unconditional promise by the maker to pay the entity (holder) a definite sum of money at a future date. Such amount may include accrued interest receivable in accordance with the terms of the note. The note also may contain provisions and related items including a discount or premium, payable on demand, secured, or unsecured, interest bearing or noninterest bearing, among a myriad of other features and characteristics. Excludes amounts related to receivables held-for-sale.

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
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