Related Party Transactions - Summary of Related Party Transactions (Details) - USD ($) $ in Millions	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Assets:
Cash and due from banks	$ 762	$ 621
Interest bearing deposits with banks	23,148	22,625
Securities purchased under agreements to resell	9,252	14,313
Trading assets	22,757	21,231
Loans	59,452	62,216	$ 58,396
Other	6,261	6,053
Total assets	172,410	170,731	168,238
Liabilities:
Deposits	124,097	123,350	$ 121,283
Trading liabilities	2,355	3,907
Short-term borrowings	7,289	7,352
Long-term debt	23,026	20,717
Other liabilities	3,204	2,916
Total liabilities	159,971	158,242
Related Party
Assets:
Cash and due from banks	304	188
Interest bearing deposits with banks	11	4
Securities purchased under agreements to resell	0	405
Trading assets	225	120
Loans	6,035	5,449
Other	469	468
Total assets	7,044	6,634
Liabilities:
Deposits	11,491	8,351
Trading liabilities	95	77
Short-term borrowings	1,960	1,549
Long-term debt	10,137	8,388
Other liabilities	295	252
Total liabilities	$ 23,978	$ 18,617