Finance Receivables - Contractual Maturities (Details) - USD ($)	Dec. 31, 2021	Dec. 31, 2020
Finance Receivables Maturity [Abstract]
Financing Receivable, Gross	$ 93,275,000,000	$ 106,375,000,000
Finance receivables before unearned interest supplements	7,318,000,000	8,431,000,000
Consumer Segment [Member]
Finance Receivables Maturity [Abstract]
Financing Receivable, Gross	73,545,000,000	78,170,000,000
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	2,676,000,000	2,599,000,000
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	6,692,000,000	6,790,000,000
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	12,875,000,000	13,939,000,000
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	22,967,000,000	21,074,000,000
Financing Receivable, Year One, Originated, Current Fiscal Year	27,467,000,000	32,923,000,000
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	868,000,000	845,000,000
Consumer Segment [Member] | Percent of Total
Finance Receivables Maturity [Abstract]
Financing Receivable, Gross	1.000	1.000
Consumer Segment [Member] | 31-60 Days Past Due [Member]
Finance Receivables Maturity [Abstract]
Financing Receivable, Gross	586,000,000	681,000,000
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	52,000,000	62,000,000
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	98,000,000	103,000,000
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	120,000,000	162,000,000
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	186,000,000	166,000,000
Financing Receivable, Year One, Originated, Current Fiscal Year	91,000,000	143,000,000
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	39,000,000	45,000,000
Consumer Segment [Member] | 31-60 Days Past Due [Member] | Percent of Total
Finance Receivables Maturity [Abstract]
Financing Receivable, Gross	0.008	0.009
Consumer Segment [Member] | Financing Receivables, 61-120 Days past due [Member]
Finance Receivables Maturity [Abstract]
Financing Receivable, Gross	127,000,000	163,000,000
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	10,000,000	12,000,000
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	20,000,000	24,000,000
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	29,000,000	44,000,000
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	40,000,000	45,000,000
Financing Receivable, Year One, Originated, Current Fiscal Year	21,000,000	31,000,000
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	7,000,000	7,000,000
Consumer Segment [Member] | Financing Receivables, 61-120 Days past due [Member] | Percent of Total
Finance Receivables Maturity [Abstract]
Financing Receivable, Gross	0.002	0.002
Consumer Segment [Member] | Greater Than 120 Days Past Due [Member]
Finance Receivables Maturity [Abstract]
Financing Receivable, Gross	43,000,000	41,000,000
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	6,000,000	6,000,000
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	6,000,000	7,000,000
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	9,000,000	8,000,000
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	11,000,000	7,000,000
Financing Receivable, Year One, Originated, Current Fiscal Year	1,000,000	2,000,000
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	10,000,000	11,000,000
Consumer Segment [Member] | Greater Than 120 Days Past Due [Member] | Percent of Total
Finance Receivables Maturity [Abstract]
Financing Receivable, Gross	0	0
Consumer Segment [Member] | Total past due [Member]
Finance Receivables Maturity [Abstract]
Financing Receivable, Gross	756,000,000	885,000,000
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	68,000,000	80,000,000
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	124,000,000	134,000,000
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	158,000,000	214,000,000
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	237,000,000	218,000,000
Financing Receivable, Year One, Originated, Current Fiscal Year	113,000,000	176,000,000
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	56,000,000	63,000,000
Consumer Segment [Member] | Total past due [Member] | Percent of Total
Finance Receivables Maturity [Abstract]
Financing Receivable, Gross	0.010	0.011
Consumer Segment [Member] | Financial Asset, 1 to 29 Days Past Due [Member]
Finance Receivables Maturity [Abstract]
Financing Receivable, Gross	72,789,000,000	77,285,000,000
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	2,608,000,000	2,519,000,000
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	6,568,000,000	6,656,000,000
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	12,717,000,000	13,725,000,000
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	22,730,000,000	20,856,000,000
Financing Receivable, Year One, Originated, Current Fiscal Year	27,354,000,000	32,747,000,000
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	812,000,000	782,000,000
Consumer Segment [Member] | Financial Asset, 1 to 29 Days Past Due [Member] | Percent of Total
Finance Receivables Maturity [Abstract]
Financing Receivable, Gross	0.990	0.989
Consumer Segment [Member] | Retail [Member]
Finance Receivables Maturity [Abstract]
Financing Receivable, Gross	73,545,000,000	78,170,000,000
Finance receivables before unearned interest supplements	76,565,000,000	82,157,000,000
Non-Consumer Segment [Member]
Finance Receivables Maturity [Abstract]
Financing Receivable, Gross	19,730,000,000	28,205,000,000
Non-Consumer Segment [Member] | Wholesale and Dealer Loans [Member]
Finance Receivables Maturity [Abstract]
Financing Receivable, Gross	18,197,000,000	26,517,000,000
Non-Consumer Segment [Member] | Other Finance Receivables [Member]
Finance Receivables Maturity [Abstract]
Financing Receivable, Gross	$ 1,533,000,000	$ 1,688,000,000