Short-Term and Long-Term Debt - Short-Term Debt (Details) - USD ($) $ in Millions	Sep. 30, 2021	Dec. 31, 2020
Short-Term Debt [Line Items]
Federal funds purchased and securities sold under agreements to repurchase	$ 363	$ 0
Federal funds purchased and securities sold under agreements to repurchase
Short-Term Debt [Line Items]
Short-term debt, weighted-average interest rate (percent)	(0.04%)	0.00%
Fannie Mae
Short-Term Debt [Line Items]
Short-term debt, outstanding	$ 8,045	$ 12,173
Short-term debt, weighted-average interest rate (percent)	0.03%	0.18%

Amount after offset of short term borrowing where a bank borrows, at the federal funds rate, from another bank and securities that an entity sells and agrees to repurchase at a specified date for a specified price.

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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.

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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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- Definition

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

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