Loans - Consumer Banking Portfolio by Credit Quality Indicator (Details) - USD ($) $ in Millions	Sep. 30, 2022	Dec. 31, 2021
Financing Receivable, Credit Quality Indicator [Line Items]
Total	$ 303,943	$ 277,340
Consumer Banking
Financing Receivable, Credit Quality Indicator [Line Items]
Term loans by vintage year one	27,447	38,021
Term loans by vintage year two	28,364	18,865
Term loans by vintage year three	12,996	10,789
Term loans by vintage year four	6,965	5,487
Term loans by vintage year five	3,161	2,816
Term loans by vintage after year five	1,820	1,287
Total term loans	80,753	77,265
Revolving loans	439	373
Revolving loans converted to term	7	8
Total	81,199	77,646
Auto \| Consumer Banking
Financing Receivable, Credit Quality Indicator [Line Items]
Term loans by vintage year one	27,294	37,736
Term loans by vintage year two	28,226	18,687
Term loans by vintage year three	12,904	10,615
Term loans by vintage year four	6,828	5,318
Term loans by vintage year five	3,024	2,639
Term loans by vintage after year five	1,304	784
Total term loans	79,580	75,779
Revolving loans	0	0
Revolving loans converted to term	0	0
Total	79,580	75,779
Retail banking \| Consumer Banking
Financing Receivable, Credit Quality Indicator [Line Items]
Term loans by vintage year one	153	285
Term loans by vintage year two	138	178
Term loans by vintage year three	92	174
Term loans by vintage year four	137	169
Term loans by vintage year five	137	177
Term loans by vintage after year five	516	503
Total term loans	1,173	1,486
Revolving loans	439	373
Revolving loans converted to term	7	8
Total	1,619	1,867
PPP loans	38	232
Current \| Retail banking \| Consumer Banking
Financing Receivable, Credit Quality Indicator [Line Items]
Term loans by vintage year one	153	285
Term loans by vintage year two	136	171
Term loans by vintage year three	91	172
Term loans by vintage year four	135	161
Term loans by vintage year five	130	176
Term loans by vintage after year five	505	491
Total term loans	1,150	1,456
Revolving loans	425	345
Revolving loans converted to term	5	6
Total	1,580	1,807
30-59 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	2
Term loans by vintage year three	0	2
Term loans by vintage year four	0	7
Term loans by vintage year five	4	0
Term loans by vintage after year five	2	1
Total term loans	7	12
Revolving loans	8	23
Revolving loans converted to term	0	0
Total	15	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	2	0
Term loans by vintage year five	0	0
Term loans by vintage after year five	0	2
Total term loans	3	6
Revolving loans	2	1
Revolving loans converted to term	0	0
Total	5	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	1	0
Term loans by vintage year four	0	1
Term loans by vintage year five	3	1
Term loans by vintage after year five	9	9
Total term loans	13	12
Revolving loans	4	4
Revolving loans converted to term	2	2
Total	19	18
Greater than 660 \| Auto \| Consumer Banking
Financing Receivable, Credit Quality Indicator [Line Items]
Term loans by vintage year one	15,488	20,758
Term loans by vintage year two	15,559	8,630
Term loans by vintage year three	6,005	4,739
Term loans by vintage year four	3,020	2,394
Term loans by vintage year five	1,300	1,153
Term loans by vintage after year five	502	301
Total term loans	41,874	37,975
Revolving loans	0	0
Revolving loans converted to term	0	0
Total	41,874	37,975
621-660 \| Auto \| Consumer Banking
Financing Receivable, Credit Quality Indicator [Line Items]
Term loans by vintage year one	5,301	7,456
Term loans by vintage year two	5,543	3,721
Term loans by vintage year three	2,535	2,109
Term loans by vintage year four	1,349	1,084
Term loans by vintage year five	626	537
Term loans by vintage after year five	270	157
Total term loans	15,624	15,064
Revolving loans	0	0
Revolving loans converted to term	0	0
Total	15,624	15,064
620 or below \| Auto \| Consumer Banking
Financing Receivable, Credit Quality Indicator [Line Items]
Term loans by vintage year one	6,505	9,522
Term loans by vintage year two	7,124	6,336
Term loans by vintage year three	4,364	3,767
Term loans by vintage year four	2,459	1,840
Term loans by vintage year five	1,098	949
Term loans by vintage after year five	532	326
Total term loans	22,082	22,740
Revolving loans	0	0
Revolving loans converted to term	0	0
Total	$ 22,082	$ 22,740

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Financing receivable past due and not past due under paycheck protection program

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

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