Loans - Consumer Banking Portfolio by Credit Quality Indicator (Details) - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021
Financing Receivable, Credit Quality Indicator [Line Items]
Total	$ 312,331	$ 277,340
Consumer Banking
Financing Receivable, Credit Quality Indicator [Line Items]
Term loans by vintage year one	31,969	38,021
Term loans by vintage year two	25,937	18,865
Term loans by vintage year three	11,591	10,789
Term loans by vintage year four	6,039	5,487
Term loans by vintage year five	2,589	2,816
Term loans by vintage after year five	1,372	1,287
Total term loans	79,497	77,265
Revolving loans	422	373
Revolving loans converted to term	6	8
Total	79,925	77,646
Auto \| Consumer Banking
Financing Receivable, Credit Quality Indicator [Line Items]
Term loans by vintage year one	31,801	37,736
Term loans by vintage year two	25,807	18,687
Term loans by vintage year three	11,509	10,615
Term loans by vintage year four	5,906	5,318
Term loans by vintage year five	2,459	2,639
Term loans by vintage after year five	891	784
Total term loans	78,373	75,779
Revolving loans	0	0
Revolving loans converted to term	0	0
Total	78,373	75,779
Retail banking \| Consumer Banking
Financing Receivable, Credit Quality Indicator [Line Items]
Term loans by vintage year one	168	285
Term loans by vintage year two	130	178
Term loans by vintage year three	82	174
Term loans by vintage year four	133	169
Term loans by vintage year five	130	177
Term loans by vintage after year five	481	503
Total term loans	1,124	1,486
Revolving loans	422	373
Revolving loans converted to term	6	8
Total	1,552	1,867
Current \| Retail banking \| Consumer Banking
Financing Receivable, Credit Quality Indicator [Line Items]
Term loans by vintage year one	166	285
Term loans by vintage year two	128	171
Term loans by vintage year three	82	172
Term loans by vintage year four	133	161
Term loans by vintage year five	127	176
Term loans by vintage after year five	470	491
Total term loans	1,106	1,456
Revolving loans	408	345
Revolving loans converted to term	4	6
Total	1,518	1,807
30-59 days \| Retail banking \| Consumer Banking
Financing Receivable, Credit Quality Indicator [Line Items]
Term loans by vintage year one	2	0
Term loans by vintage year two	1	2
Term loans by vintage year three	0	2
Term loans by vintage year four	0	7
Term loans by vintage year five	0	0
Term loans by vintage after year five	2	1
Total term loans	5	12
Revolving loans	8	23
Revolving loans converted to term	0	0
Total	13	35
60-89 days \| Retail banking \| Consumer Banking
Financing Receivable, Credit Quality Indicator [Line Items]
Term loans by vintage year one	0	0
Term loans by vintage year two	1	4
Term loans by vintage year three	0	0
Term loans by vintage year four	0	0
Term loans by vintage year five	0	0
Term loans by vintage after year five	1	2
Total term loans	2	6
Revolving loans	2	1
Revolving loans converted to term	0	0
Total	4	7
Greater than 90 days \| Retail banking \| Consumer Banking
Financing Receivable, Credit Quality Indicator [Line Items]
Term loans by vintage year one	0	0
Term loans by vintage year two	0	1
Term loans by vintage year three	0	0
Term loans by vintage year four	0	1
Term loans by vintage year five	3	1
Term loans by vintage after year five	8	9
Total term loans	11	12
Revolving loans	4	4
Revolving loans converted to term	2	2
Total	17	18
Greater than 660 \| Auto \| Consumer Banking
Financing Receivable, Credit Quality Indicator [Line Items]
Term loans by vintage year one	17,872	20,758
Term loans by vintage year two	14,246	8,630
Term loans by vintage year three	5,354	4,739
Term loans by vintage year four	2,595	2,394
Term loans by vintage year five	1,032	1,153
Term loans by vintage after year five	328	301
Total term loans	41,427	37,975
Revolving loans	0	0
Revolving loans converted to term	0	0
Total	41,427	37,975
621-660 \| Auto \| Consumer Banking
Financing Receivable, Credit Quality Indicator [Line Items]
Term loans by vintage year one	6,212	7,456
Term loans by vintage year two	5,060	3,721
Term loans by vintage year three	2,257	2,109
Term loans by vintage year four	1,167	1,084
Term loans by vintage year five	513	537
Term loans by vintage after year five	185	157
Total term loans	15,394	15,064
Revolving loans	0	0
Revolving loans converted to term	0	0
Total	15,394	15,064
620 or below \| Auto \| Consumer Banking
Financing Receivable, Credit Quality Indicator [Line Items]
Term loans by vintage year one	7,717	9,522
Term loans by vintage year two	6,501	6,336
Term loans by vintage year three	3,898	3,767
Term loans by vintage year four	2,144	1,840
Term loans by vintage year five	914	949
Term loans by vintage after year five	378	326
Total term loans	21,552	22,740
Revolving loans	0	0
Revolving loans converted to term	0	0
Total	$ 21,552	$ 22,740

Financing Receivable, Excluding Accrued Interest, Before Allowance for Credit Loss, Term Loans

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- Definition

Amortized cost excluding accrued interest, before allowance for credit loss, of financing receivable. Excludes net investment in lease.

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Amortized cost excluding accrued interest, of financing receivable originated more than five years prior to current fiscal year. Excludes net investment in lease.

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Amortized cost excluding accrued interest, of financing receivable that can be withdrawn, repaid, and redrawn.

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Amortized cost excluding accrued interest, of financing receivable originated three years prior to current fiscal year. Excludes net investment in lease.

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Amortized cost excluding accrued interest, of financing receivable originated in current fiscal year. Excludes net investment in lease.

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