Other Short-Term Borrowings - Summary of Other Short-Term Borrowings (Details) - USD ($) $ in Millions	Jun. 30, 2024	Dec. 31, 2023
Short-Term Debt [Abstract]
FHLB advances	$ 3,000	$ 2,500
Securities sold under repurchase agreements	300	330
Derivative collateral	35	3
Other borrowed money	35	28
Other short-term borrowings	$ 3,370	$ 2,861