Other Short-Term Borrowings - Summary of Other Short-Term Borrowings (Details) - USD ($) $ in Millions	Sep. 30, 2024	Dec. 31, 2023
Short-Term Debt [Abstract]
FHLB advances	$ 1,000	$ 2,500
Securities sold under repurchase agreements	321	330
Derivative collateral	57	3
Other borrowed money	46	28
Total other short-term borrowings	$ 1,424	$ 2,861