Loans - Trouble Debt Restructurings (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total Loans Modified	$ 2,252	$ 812	$ 1,489
Credit Card
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total Loans Modified	$ 433	$ 277	$ 411
Credit Card | Reduced Interest Rate
Financing Receivable, Troubled Debt Restructuring [Line Items]
% of TDR Activity	100.00%	100.00%	100.00%
Average Rate Reduction	19.73%	21.15%	20.61%
Consumer Banking
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total Loans Modified	$ 1,077	$ 374	$ 541
Consumer Banking | Reduced Interest Rate
Financing Receivable, Troubled Debt Restructuring [Line Items]
% of TDR Activity	57.00%	42.00%	11.00%
Average Rate Reduction	8.53%	8.70%	5.73%
Consumer Banking | Term Extension
Financing Receivable, Troubled Debt Restructuring [Line Items]
% of TDR Activity	97.00%	93.00%	94.00%
Average Term Extension (Months)	4 months	4 months	3 months
Consumer Banking | Principal Forgiveness
Financing Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivables, Impaired, Write-down Percentage of Troubled Debt Restructuring Activity		0.00%	0.00%
Gross Balance Reduction		$ 1	$ 1
Consumer Banking | Auto
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total Loans Modified	$ 1,070	$ 371	$ 536
Consumer Banking | Auto | Reduced Interest Rate
Financing Receivable, Troubled Debt Restructuring [Line Items]
% of TDR Activity	57.00%	43.00%	11.00%
Average Rate Reduction	8.53%	8.72%	5.68%
Consumer Banking | Auto | Term Extension
Financing Receivable, Troubled Debt Restructuring [Line Items]
% of TDR Activity	97.00%	93.00%	95.00%
Average Term Extension (Months)	4 months	4 months	3 months
Consumer Banking | Auto | Principal Forgiveness
Financing Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivables, Impaired, Write-down Percentage of Troubled Debt Restructuring Activity		0.00%	0.00%
Gross Balance Reduction		$ 1	$ 1
Consumer Banking | Retail banking
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total Loans Modified	$ 7	$ 3	$ 5
Consumer Banking | Retail banking | Reduced Interest Rate
Financing Receivable, Troubled Debt Restructuring [Line Items]
% of TDR Activity		13.00%	11.00%
Average Rate Reduction		2.94%	10.86%
Consumer Banking | Retail banking | Term Extension
Financing Receivable, Troubled Debt Restructuring [Line Items]
% of TDR Activity	92.00%	30.00%	20.00%
Average Term Extension (Months)	13 months	42 months	8 months
Commercial Banking
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total Loans Modified	$ 742	$ 161	$ 537
Commercial Banking | Reduced Interest Rate
Financing Receivable, Troubled Debt Restructuring [Line Items]
% of TDR Activity	4.00%	6.00%	3.00%
Average Rate Reduction	0.28%	1.19%	0.14%
Commercial Banking | Term Extension
Financing Receivable, Troubled Debt Restructuring [Line Items]
% of TDR Activity	74.00%	46.00%	58.00%
Average Term Extension (Months)	13 months	9 months	17 months
Commercial Banking | Principal Forgiveness
Financing Receivable, Troubled Debt Restructuring [Line Items]
% of TDR Activity			3.00%
Gross Balance Reduction			$ 7
Commercial Banking | Commercial and multifamily real estate
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total Loans Modified	$ 385	$ 49	$ 98
Commercial Banking | Commercial and multifamily real estate | Reduced Interest Rate
Financing Receivable, Troubled Debt Restructuring [Line Items]
% of TDR Activity	8.00%	21.00%
Average Rate Reduction	0.28%	1.19%
Commercial Banking | Commercial and multifamily real estate | Term Extension
Financing Receivable, Troubled Debt Restructuring [Line Items]
% of TDR Activity	84.00%	85.00%	86.00%
Average Term Extension (Months)	13 months	11 months	5 months
Commercial Banking | Commercial And Industrial [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total Loans Modified	$ 357	$ 112	$ 439
Commercial Banking | Commercial And Industrial [Member] | Reduced Interest Rate
Financing Receivable, Troubled Debt Restructuring [Line Items]
% of TDR Activity			4.00%
Average Rate Reduction			0.14%
Commercial Banking | Commercial And Industrial [Member] | Term Extension
Financing Receivable, Troubled Debt Restructuring [Line Items]
% of TDR Activity	64.00%	30.00%	52.00%
Average Term Extension (Months)	13 months	6 months	21 months
Commercial Banking | Commercial And Industrial [Member] | Principal Forgiveness
Financing Receivable, Troubled Debt Restructuring [Line Items]
% of TDR Activity			4.00%
Gross Balance Reduction			$ 7
Domestic credit card: | Credit Card
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total Loans Modified	$ 306	$ 154	$ 243
Domestic credit card: | Credit Card | Reduced Interest Rate
Financing Receivable, Troubled Debt Restructuring [Line Items]
% of TDR Activity	100.00%	100.00%	100.00%
Average Rate Reduction	16.54%	15.90%	15.94%
International card businesses: | Credit Card
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total Loans Modified	$ 127	$ 123	$ 168
International card businesses: | Credit Card | Reduced Interest Rate
Financing Receivable, Troubled Debt Restructuring [Line Items]
% of TDR Activity	100.00%	100.00%	100.00%
Average Rate Reduction	27.42%	27.70%	27.38%