Short-Term Borrowings - Outstanding and Weighted-Average Interest Rates of Short-Term Borrowings (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Short-term Debt [Line Items]
Weighted-average interest rate as of year-end	0.83%	0.31%
Securities Sold Under Repurchase Agreements
Short-term Debt [Line Items]
Balance as of December 31	$ 1,177	$ 1,575	$ 3,413
Maximum outstanding as of any month-end	11,517	1,575	5,373
Average outstanding during the year	$ 3,633	$ 667	$ 2,615
Weighted-average interest rate as of year-end	2.31%	0.00%	0.00%
Weighted-average interest rate during the year	0.39%	(0.00%)	0.14%
Tax-Exempt Investment Program
Short-term Debt [Line Items]
Balance as of December 31	$ 0	$ 0	$ 616
Maximum outstanding as of any month-end	0	616	823
Average outstanding during the year	$ 0	$ 523	$ 771
Weighted-average interest rate as of year-end	0.00%	0.00%	0.23%
Weighted-average interest rate during the year	0.00%	0.31%	0.78%
Other
Short-term Debt [Line Items]
Balance as of December 31	$ 2,000	$ 0	$ 3,302
Maximum outstanding as of any month-end	8,525	0	25,665
Average outstanding during the year	$ 696	$ 315	$ 8,251
Weighted-average interest rate as of year-end	4.18%	0.00%	1.35%
Weighted-average interest rate during the year	0.01%	0.00%	1.23%

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- Definition

Reflects the total carrying amount as of the balance sheet date of debt having initial terms less than one year or the normal operating cycle, if longer.

+ References

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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Weighted average interest rate of short-term debt outstanding calculated at point in time.

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For the form of debt having an initial term of less than one year or less than the normal operating cycle, if longer, average borrowings during the period.

+ References

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-Publisher SEC
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For the form of debt having an initial term of less than one year or less than the normal operating cycle, if longer, maximum month-end borrowings during the period.

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