Related Party Transactions - Summary of Related Party Transactions (Details) - USD ($) $ in Millions		Sep. 30, 2025		Dec. 31, 2024		Sep. 30, 2024
Assets:
Cash and due from banks	[1]	$ 1,099		$ 621
Interest bearing deposits with banks	[1]	23,995		22,625
Securities purchased under agreements to resell	[1]	4,851		14,313
Trading assets	[1]	19,905		21,231
Loans, net		63,978	[1]	62,216	[1]	$ 61,467
Other	[1]	6,629		6,053
Total assets		169,890	[1]	170,731	[1]	167,799
Liabilities:
Deposits		122,760	[1]	123,350	[1]	$ 123,373
Trading liabilities	[1]	2,477		3,907
Short-term borrowings	[1]	6,309		7,352
Long-term debt	[1]	23,183		20,717
Other liabilities	[1]	3,170		2,916
Total liabilities	[1]	157,899		158,242
Related Party
Assets:
Cash and due from banks		645		188
Interest bearing deposits with banks		7		4
Securities purchased under agreements to resell		0		405
Trading assets		6		120
Loans, net		6,417		5,449
Other		444		468
Total assets		7,519		6,634
Liabilities:
Deposits		9,953		8,351
Trading liabilities		140		77
Short-term borrowings		1,158		1,549
Long-term debt		10,136		8,388
Other liabilities		352		252
Total liabilities		$ 21,739		$ 18,617

[1] The following table summarizes assets and liabilities related to our consolidated variable interest entities ("VIEs") at September 30, 2025 and December 31, 2024. Assets and liabilities exclude intercompany balances that eliminate in consolidation. See Note 15, "Variable Interest Entities," for additional information. September 30, 2025December 31, 2024(in millions)AssetsOther assets$7 $11 Total assets$7 $11 LiabilitiesInterest, taxes and other liabilities$14 $4 Total liabilities$14 $4