Loans - Consumer, Excluding Credit Card Loan Portfolio, Residential Real Estate, Nonaccrual Loans and Other Credit Quality Indicators (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Loans and Leases Receivable Disclosure [Line Items]
Retained loans	$ 1,280,870	$ 1,089,598	$ 1,010,206
Consumer, excluding credit card
Loans and Leases Receivable Disclosure [Line Items]
Retained loans	397,275	300,753	$ 295,556
Consumer, excluding credit card | First Republic
Loans and Leases Receivable Disclosure [Line Items]
Retained loans	90,700
Consumer, excluding credit card | Residential real estate
Loans and Leases Receivable Disclosure [Line Items]
Nonaccrual loans	3,466	3,745
Retained loans	$ 326,409	$ 237,561
Weighted average LTV ratio	49.00%	51.00%
Weighted average FICO	770	769
Approximate percentage of Chapter 7 loans 30 days or more past due	9.00%
Interest income on nonaccrual loans recognized on a cash basis	$ 180	$ 175
Consumer, excluding credit card | Residential real estate | First Republic
Loans and Leases Receivable Disclosure [Line Items]
Retained loans	90,700
Consumer, excluding credit card | Residential real estate | California
Loans and Leases Receivable Disclosure [Line Items]
Retained loans	127,072	73,112
Consumer, excluding credit card | Residential real estate | California | First Republic
Loans and Leases Receivable Disclosure [Line Items]
Retained loans	54,900
Consumer, excluding credit card | Residential real estate | New York
Loans and Leases Receivable Disclosure [Line Items]
Retained loans	48,815	34,471
Consumer, excluding credit card | Residential real estate | New York | First Republic
Loans and Leases Receivable Disclosure [Line Items]
Retained loans	14,900
Consumer, excluding credit card | Residential real estate | Florida
Loans and Leases Receivable Disclosure [Line Items]
Retained loans	22,778	18,870
Consumer, excluding credit card | Residential real estate | Florida | First Republic
Loans and Leases Receivable Disclosure [Line Items]
Retained loans	3,500
Consumer, excluding credit card | Residential real estate | Texas
Loans and Leases Receivable Disclosure [Line Items]
Retained loans	15,506	14,968
Consumer, excluding credit card | Residential real estate | Massachusetts
Loans and Leases Receivable Disclosure [Line Items]
Retained loans	14,213	6,380
Consumer, excluding credit card | Residential real estate | Massachusetts | First Republic
Loans and Leases Receivable Disclosure [Line Items]
Retained loans	7,800
Consumer, excluding credit card | Residential real estate | Illinois
Loans and Leases Receivable Disclosure [Line Items]
Retained loans	10,856	11,296
Consumer, excluding credit card | Residential real estate | Colorado
Loans and Leases Receivable Disclosure [Line Items]
Retained loans	10,800	9,968
Consumer, excluding credit card | Residential real estate | Washington
Loans and Leases Receivable Disclosure [Line Items]
Retained loans	9,923	9,060
Consumer, excluding credit card | Residential real estate | New Jersey
Loans and Leases Receivable Disclosure [Line Items]
Retained loans	8,050	7,108
Consumer, excluding credit card | Residential real estate | Connecticut
Loans and Leases Receivable Disclosure [Line Items]
Retained loans	7,163	5,432
Consumer, excluding credit card | Residential real estate | All other
Loans and Leases Receivable Disclosure [Line Items]
Retained loans	51,233	46,896
Consumer, excluding credit card | Residential real estate | No FICO/LTV available
Loans and Leases Receivable Disclosure [Line Items]
Retained loans	989	1,406
Consumer, excluding credit card | Residential real estate | Greater than 125% and refreshed FICO scores | Equal to or greater than 660
Loans and Leases Receivable Disclosure [Line Items]
Retained loans	72	2
Consumer, excluding credit card | Residential real estate | Greater than 125% and refreshed FICO scores | Less than 660
Loans and Leases Receivable Disclosure [Line Items]
Retained loans	0	0
Consumer, excluding credit card | Residential real estate | 101% to 125% and refreshed FICO scores | Equal to or greater than 660
Loans and Leases Receivable Disclosure [Line Items]
Retained loans	223	174
Consumer, excluding credit card | Residential real estate | 101% to 125% and refreshed FICO scores | Less than 660
Loans and Leases Receivable Disclosure [Line Items]
Retained loans	4	6
Consumer, excluding credit card | Residential real estate | 80% to 100% and refreshed FICO scores | Equal to or greater than 660
Loans and Leases Receivable Disclosure [Line Items]
Retained loans	6,491	12,034
Consumer, excluding credit card | Residential real estate | 80% to 100% and refreshed FICO scores | Equal to or greater than 660 | First Republic
Loans and Leases Receivable Disclosure [Line Items]
Retained loans	1,100
Consumer, excluding credit card | Residential real estate | 80% to 100% and refreshed FICO scores | Less than 660
Loans and Leases Receivable Disclosure [Line Items]
Retained loans	102	184
Consumer, excluding credit card | Residential real estate | Lower than 80% and refreshed FICO scores | Equal to or greater than 660
Loans and Leases Receivable Disclosure [Line Items]
Retained loans	309,251	215,096
Consumer, excluding credit card | Residential real estate | Lower than 80% and refreshed FICO scores | Equal to or greater than 660 | First Republic
Loans and Leases Receivable Disclosure [Line Items]
Retained loans	87,900
Consumer, excluding credit card | Residential real estate | Lower than 80% and refreshed FICO scores | Less than 660
Loans and Leases Receivable Disclosure [Line Items]
Retained loans	9,277	$ 8,659
Consumer, excluding credit card | Residential real estate | Lower than 80% and refreshed FICO scores | Less than 660 | First Republic
Loans and Leases Receivable Disclosure [Line Items]
Retained loans	$ 1,100