Short-Term Borrowings - Outstanding and Weighted-Average Interest Rates of Short-Term Borrowings (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023
Short-term Debt [Line Items]
Weighted-average interest rate as of year-end	5.03%	1.52%
Securities Sold Under Repurchase Agreements
Short-term Debt [Line Items]
Balance as of December 31	$ 3,681	$ 1,867
Average outstanding during the year	$ 3,163	$ 3,904
Weighted-average interest rate as of year-end	5.62%	0.08%
Weighted-average interest rate during the year	4.93%	0.87%
Other
Short-term Debt [Line Items]
Balance as of December 31	$ 9,815	$ 3,500
Average outstanding during the year	$ 11,128	$ 849
Weighted-average interest rate as of year-end	4.77%	3.03%
Weighted-average interest rate during the year	5.19%	5.12%