Finance Receivables - Aging Analysis (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Finance Receivables Aging Analysis [Abstract]
Financing Receivable, Gross	$ 113,705	$ 101,358
Consumer Segment [Member]
Finance Receivables Aging Analysis [Abstract]
Financing Receivable, Gross	78,392	71,503
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	947	942
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	2,424	2,640
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	7,562	6,265
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	11,497	14,091
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	20,536	18,579
Financing Receivable, Year One, Originated, Current Fiscal Year	35,426	28,986
Non-Consumer Segment [Member]
Finance Receivables Aging Analysis [Abstract]
Financing Receivable, Gross	35,313	29,855
Financing Receivable, Revolving	32,262	27,261
Non-Consumer Segment [Member] | Dealer Loan
Finance Receivables Aging Analysis [Abstract]
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	399	404
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	31	169
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	59	36
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	159	72
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	64	187
Financing Receivable, Year One, Originated, Current Fiscal Year	403	279
Non-Consumer Segment [Member] | Group I [Member]
Finance Receivables Aging Analysis [Abstract]
Financing Receivable, Gross	30,132	25,303
Financing Receivable, Revolving	29,095	24,242
Non-Consumer Segment [Member] | Group I [Member] | Dealer Loan
Finance Receivables Aging Analysis [Abstract]
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	383	402
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	30	148
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	58	35
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	156	67
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	61	185
Financing Receivable, Year One, Originated, Current Fiscal Year	349	224
Non-Consumer Segment [Member] | Group II [Member]
Finance Receivables Aging Analysis [Abstract]
Financing Receivable, Gross	2,900	2,823
Financing Receivable, Revolving	2,834	2,751
Non-Consumer Segment [Member] | Group II [Member] | Dealer Loan
Finance Receivables Aging Analysis [Abstract]
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	16	2
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	0	21
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	1	0
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	3	5
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	2	2
Financing Receivable, Year One, Originated, Current Fiscal Year	44	42
Non-Consumer Segment [Member] | Group III [Member]
Finance Receivables Aging Analysis [Abstract]
Financing Receivable, Gross	301	243
Financing Receivable, Revolving	292	233
Non-Consumer Segment [Member] | Group III [Member] | Dealer Loan
Finance Receivables Aging Analysis [Abstract]
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	0	0
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	0	0
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	0	0
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	0	0
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	1	0
Financing Receivable, Year One, Originated, Current Fiscal Year	8	10
Non-Consumer Segment [Member] | Group IV [Member]
Finance Receivables Aging Analysis [Abstract]
Financing Receivable, Gross	44	39
Financing Receivable, Revolving	41	35
Non-Consumer Segment [Member] | Group IV [Member] | Dealer Loan
Finance Receivables Aging Analysis [Abstract]
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	0	0
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	1	0
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	0	1
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	0	0
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	0	0
Financing Receivable, Year One, Originated, Current Fiscal Year	2	3
Financial Asset, 1 to 29 Days Past Due [Member] | Consumer Segment [Member]
Finance Receivables Aging Analysis [Abstract]
Financing Receivable, Gross	77,464	70,667
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	891	883
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	2,360	2,564
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	7,395	6,149
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	11,325	13,864
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	20,281	18,382
Financing Receivable, Year One, Originated, Current Fiscal Year	35,212	28,825
31-60 Days Past Due [Member] | Consumer Segment [Member]
Finance Receivables Aging Analysis [Abstract]
Financing Receivable, Gross	690	649
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	40	41
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	49	60
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	130	91
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	125	181
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	187	150
Financing Receivable, Year One, Originated, Current Fiscal Year	159	126
Financing Receivables, 61-120 Days past due [Member] | Consumer Segment [Member]
Finance Receivables Aging Analysis [Abstract]
Financing Receivable, Gross	195	149
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	9	9
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	11	12
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	30	20
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	37	39
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	58	40
Financing Receivable, Year One, Originated, Current Fiscal Year	50	29
Greater Than 120 Days Past Due [Member] | Consumer Segment [Member]
Finance Receivables Aging Analysis [Abstract]
Financing Receivable, Gross	43	38
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	7	9
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	4	4
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	7	5
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	10	7
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	10	7
Financing Receivable, Year One, Originated, Current Fiscal Year	5	6
Total past due [Member] | Consumer Segment [Member]
Finance Receivables Aging Analysis [Abstract]
Financing Receivable, Gross	928	836
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	56	59
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	64	76
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	167	116
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	172	227
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	255	197
Financing Receivable, Year One, Originated, Current Fiscal Year	$ 214	$ 161