Loans and Related Allowance for Credit Losses, Loans Outstanding (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Dec. 31, 2023
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	$ 909,711	$ 942,424	$ 936,682
Accounts, Notes, Loans and Financing Receivable Textual [Abstract]
Deferred income as a percentage of total loans outstanding	1.00%		1.00%
Total Commercial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	$ 530,642		$ 547,427
Accounts, Notes, Loans and Financing Receivable Textual [Abstract]
Financing receivable, accrued interest, writeoff	33	31
Total Commercial [Member] | Non-U.S. [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	69,996		79,828
Total Commercial [Member] | Commercial and industrial loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	372,750		380,388
Total Commercial [Member] | Commercial and industrial loans [Member] | Non-U.S. [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	63,334		72,215
Total Commercial [Member] | Commercial real estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	141,410		150,616
Total Commercial [Member] | Commercial real estate [Member] | Non-U.S. [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	6,018		6,916
Total Commercial [Member] | Lease financing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Lease financing	16,482		16,423
Total Commercial [Member] | Lease financing [Member] | Non-U.S. [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Lease financing	644		697
Total Consumer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	379,069		389,255
Accounts, Notes, Loans and Financing Receivable Textual [Abstract]
Financing receivable, accrued interest, writeoff	300	$ 188
Total Consumer [Member] | Residential mortgage [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	252,676		260,724
Total Consumer [Member] | Credit card [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	55,046		52,230
Total Consumer [Member] | Auto [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	42,815		47,762
Total Consumer [Member] | Other consumer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	28,532		28,539
Total Consumer [Member] | Other consumer [Member] | Securities Based Lending Loans [Member] | Wealth Management [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	$ 20,300		$ 18,300