Fair Value Measurement - Assets Measured at Fair Value on a Nonrecurring Basis (Details) - Nonrecurring - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Certain impaired loans	$ 2,469	$ 197
Loans held for sale	335
Other assets	52	50
Total assets at fair value	2,856	247
Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Certain impaired loans	0	0
Loans held for sale	0
Other assets	0	0
Total assets at fair value	0	0
Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Certain impaired loans	0	0
Loans held for sale	335
Other assets	0	0
Total assets at fair value	335	0
Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Certain impaired loans	2,469	197
Loans held for sale	0
Other assets	52	50
Total assets at fair value	$ 2,521	$ 247