Short-Term Borrowings - Components of Other Short-Term Borrowings (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Short-term Debt [Abstract]
Securities sold under repurchase agreements	$ 544	$ 679
Derivative collateral	436	474
Other secured borrowings	0	39
Other short-term borrowings	$ 980	$ 1,192