Parent Company Financial Information - Statements of Balance Sheets (Details) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Investments in subsidiaries:
Other assets	$ 3,996	$ 4,169
Total assets	82,152	81,661
Liabilities and equity:
Term borrowings	1,195	1,150
Total liabilities	73,041	72,370
Total equity	9,111	9,291	$ 8,547	$ 8,494
Total liabilities and equity	82,152	81,661
Parent Company
Assets:
Cash	837	854
Notes receivable	3	3
Investments in subsidiaries:
Bank	8,487	8,658
Non-bank	61	49
Other assets	251	256
Total assets	9,639	9,820
Liabilities and equity:
Accrued employee benefits and other liabilities	473	324
Term borrowings	350	500
Total liabilities	823	824
Total equity	8,816	8,996
Total liabilities and equity	$ 9,639	$ 9,820