Loans - Consumer, Excluding Credit Card Loan Portfolio, Financial Effects of Modifications and Redefaults (Details) $ in Millions	12 Months Ended
	Dec. 31, 2022 USD ($) loan_payment	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)
Financing Receivable, Impaired [Line Items]
Carrying value	$ 1,089,598	$ 1,010,206	$ 960,506
Consumer, excluding credit card
Financing Receivable, Impaired [Line Items]
Carrying value	$ 300,753	295,556	$ 302,127
Consumer, excluding credit card | Residential real estate
Financing Receivable, Impaired [Line Items]
Number of payments past due for deemed payment | loan_payment	2
Carrying value	$ 237,561	224,795
Consumer, excluding credit card | Residential real estate | In Process of Active or Suspended Foreclosure
Financing Receivable, Impaired [Line Items]
Carrying value	$ 565	$ 619
Consumer, excluding credit card | Residential real estate | Maximum
Financing Receivable, Impaired [Line Items]
Number of years before payment default under a modified loan	1 year
Number of months before a payment redefault under modified loans	12 months
Consumer, excluding credit card | Residential real estate | Permanent Modification
Financing Receivable, Impaired [Line Items]
Weighted-average interest rate of loans with interest rate reductions – before TDR	4.75%	4.54%	5.09%
Weighted-average interest rate of loans with interest rate reductions – after TDR	3.35%	2.92%	3.28%
Weighted-average remaining contractual term (in years) of loans with term or payment extensions – before TDR	22 years	23 years	22 years
Weighted-average remaining contractual term (in years) of loans with term or payment extensions – after TDR	38 years	38 years	39 years
Charge-offs recognized upon permanent modification	$ 1	$ 0	$ 5
Principal deferred	16	28	16
Principal forgiven	2	1	5
Balance of loans that redefaulted within one year of permanent modification	$ 147	$ 160	$ 199
Modifications, weighted-average remaining life	6 years