Loans - Credit Card Delinquency Status (Details) - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021
Financing Receivable, Allowance for Credit Loss [Line Items]
Total	$ 312,331	$ 277,340
Credit Card
Financing Receivable, Allowance for Credit Loss [Line Items]
Revolving loans	137,394	114,361
Revolving loans converted to term	336	411
Total	137,730	114,772
Domestic credit card: | Credit Card
Financing Receivable, Allowance for Credit Loss [Line Items]
Revolving loans	131,284	108,364
Revolving loans converted to term	297	359
Total	131,581	108,723
International card businesses: | Credit Card
Financing Receivable, Allowance for Credit Loss [Line Items]
Revolving loans	6,110	5,997
Revolving loans converted to term	39	52
Total	6,149	6,049
Current | Domestic credit card: | Credit Card
Financing Receivable, Allowance for Credit Loss [Line Items]
Revolving loans	126,811	105,985
Revolving loans converted to term	255	327
Total	127,066	106,312
Current | International card businesses: | Credit Card
Financing Receivable, Allowance for Credit Loss [Line Items]
Revolving loans	5,866	5,795
Revolving loans converted to term	29	41
Total	5,895	5,836
30-59 days | Domestic credit card: | Credit Card
Financing Receivable, Allowance for Credit Loss [Line Items]
Revolving loans	1,388	760
Revolving loans converted to term	17	13
Total	1,405	773
30-59 days | International card businesses: | Credit Card
Financing Receivable, Allowance for Credit Loss [Line Items]
Revolving loans	83	73
Revolving loans converted to term	3	4
Total	86	77
60-89 days | Domestic credit card: | Credit Card
Financing Receivable, Allowance for Credit Loss [Line Items]
Revolving loans	964	519
Revolving loans converted to term	11	9
Total	975	528
60-89 days | International card businesses: | Credit Card
Financing Receivable, Allowance for Credit Loss [Line Items]
Revolving loans	55	47
Revolving loans converted to term	3	3
Total	58	50
Greater than 90 days | Domestic credit card: | Credit Card
Financing Receivable, Allowance for Credit Loss [Line Items]
Revolving loans	2,121	1,100
Revolving loans converted to term	14	10
Total	2,135	1,110
Greater than 90 days | International card businesses: | Credit Card
Financing Receivable, Allowance for Credit Loss [Line Items]
Revolving loans	106	82
Revolving loans converted to term	4	4
Total	$ 110	$ 86