Loans - Consumer, Excluding Credit Card Loan Portfolio, Residential Real Estate (Details) - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Loans and Leases Receivable Disclosure [Line Items]
Total retained loans	$ 1,089,598	$ 1,010,206	$ 960,506
Consumer, excluding credit card
Loans and Leases Receivable Disclosure [Line Items]
Total retained loans	300,753	295,556	$ 302,127
Consumer, excluding credit card | Residential real estate
Loans and Leases Receivable Disclosure [Line Items]
Term loans originated in 2022/2021	39,964	68,755
Term loans originated in 2021/2020	66,084	48,368
Term loans originated in 2020/2019	43,335	18,476
Term loans originated in 2019/2018	15,427	7,981
Term loans originated in 2018/2017	6,366	11,739
Term loans originated prior to 2018/2017	50,709	50,794
Revolving loans within revolving period	5,608	6,409
Revolving loans converted to term loans	10,068	12,273
Total retained loans	$ 237,561	$ 224,795
% of 30 plus days past due to total retained loans, Term loans originated in 2022/2021	0.08%	0.02%
% of 30 plus days past due to total retained loans, Term loans originated in 2021/2020	0.02%	0.07%
% of 30 plus days past due to total retained loans, Term loans originated in 2020/2019	0.05%	0.26%
% of 30 plus days past due to total retained loans, Term loans originated in 2019/2018	0.19%	0.65%
% of 30 plus days past due to total retained loans, Term loans originated in 2018/2017	0.42%	0.47%
% of 30 plus days past due to total retained loans, Term loans originated prior to 2018/2017	2.07%	3.18%
% of 30 plus days past due to total retained loans, Revolving loans within the revolving period	0.34%	0.27%
% of 30 plus days past due to total retained loans, Revolving loans converted to term loans	3.80%	3.80%
% of 30 plus days past due to total retained loans	0.66%	1.02%
Consumer, excluding credit card | Residential real estate | Senior lien
Loans and Leases Receivable Disclosure [Line Items]
Percentage of total revolving loans that are senior lien loans	37.00%
Consumer, excluding credit card | Residential real estate | Current
Loans and Leases Receivable Disclosure [Line Items]
Term loans originated in 2022/2021	$ 39,934	$ 68,742
Term loans originated in 2021/2020	66,072	48,334
Term loans originated in 2020/2019	43,315	18,428
Term loans originated in 2019/2018	15,397	7,929
Term loans originated in 2018/2017	6,339	11,684
Term loans originated prior to 2018/2017	49,632	49,147
Revolving loans within revolving period	5,589	6,392
Revolving loans converted to term loans	9,685	11,807
Total retained loans	235,963	222,463
Consumer, excluding credit card | Residential real estate | 30–149 days past due
Loans and Leases Receivable Disclosure [Line Items]
Term loans originated in 2022/2021	29	13
Term loans originated in 2021/2020	11	23
Term loans originated in 2020/2019	14	27
Term loans originated in 2019/2018	20	27
Term loans originated in 2018/2017	20	22
Term loans originated prior to 2018/2017	597	578
Revolving loans within revolving period	15	11
Revolving loans converted to term loans	208	182
Total retained loans	914	883
Consumer, excluding credit card | Residential real estate | 150 or more days past due
Loans and Leases Receivable Disclosure [Line Items]
Term loans originated in 2022/2021	1	0
Term loans originated in 2021/2020	1	11
Term loans originated in 2020/2019	6	21
Term loans originated in 2019/2018	10	25
Term loans originated in 2018/2017	7	33
Term loans originated prior to 2018/2017	480	1,069
Revolving loans within revolving period	4	6
Revolving loans converted to term loans	175	284
Total retained loans	$ 684	$ 1,449