Borrowed Funds - Breakdown of borrowed funds (Details) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023
Debt Instrument
Long-term debt	$ 14,426	$ 21,267
Total wholesale borrowings
Debt Instrument
Long-term debt	13,400	20,250
FHLB advances
Debt Instrument
Long-term debt	13,400	19,250
Federal Reserve Bank term funding
Debt Instrument
Long-term debt	0	1,000
Junior subordinated debentures
Debt Instrument
Long-term debt	582	579
Subordinated notes
Debt Instrument
Long-term debt	$ 444	$ 438