Debt (Schedule of Short-term Debt) (Details) - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019
Short-term Debt [Line Items]
Demand notes	$ 2,377	$ 2,581
Federal Home Loan Bank, advances	6,634	2,950
Securities sold under agreements to repurchase	482	0
Total short-term borrowings	9,493	5,531
Non-derivative Cash Collateral Placed with Counterparties Associated with the Repurchase Agreements	3	0
Non-derivative cash collateral received from counterparties associated with repurchase agreements	3	0
Non-derivative noncash collateral received from counterparties associated with repurchase agreements		0
Unsecured debt
Short-term Debt [Line Items]
Demand notes	2,377	2,581
Federal Home Loan Bank, advances	0	0
Securities sold under agreements to repurchase	0	0
Total short-term borrowings	2,377	2,581
Secured debt
Short-term Debt [Line Items]
Demand notes	0	0
Federal Home Loan Bank, advances	6,634	2,950
Securities sold under agreements to repurchase	482	0
Total short-term borrowings	7,116	$ 2,950
Secured debt \| US Treasury
Short-term Debt [Line Items]
Financial instruments sold under agreements to repurchase	104
Secured debt \| Mortgage-backed residential
Short-term Debt [Line Items]
Financial instruments sold under agreements to repurchase	378
Secured debt \| Mortgage-backed residential \| Maturity Less than 30 Days
Short-term Debt [Line Items]
Financial instruments sold under agreements to repurchase	385
Secured debt \| Mortgage-backed residential \| Maturity within 31 to 60 Days
Short-term Debt [Line Items]
Financial instruments sold under agreements to repurchase	$ 97

Demand Notes

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- Definition

Non-derivative Cash Collateral Placed with Counterparties Associated with the Repurchase Agreements

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- Definition

Non-derivative Cash Collateral received from counterparties associated with Repurchase Agreements

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- Definition

Non-derivative Noncash Collateral received from counterparties associated with Repurchase Agreements

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- Definition

Carrying amount of assets sold under agreements to repurchase when the carrying amount (or market value, if higher than the carrying amount) of securities or other assets sold under repurchase agreements exceeds 10 percent of total assets.

+ References

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Amount of advances from Federal Home Loan Bank (FHLBank) maturing in the next fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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- Definition

Amount, before effects of master netting arrangements, of funds outstanding borrowed in the form of a security repurchase agreement between the entity and another party for the sale and repurchase of identical or substantially the same securities at a date certain for a specified price. Includes liabilities elected not to be offset. Excludes liabilities not subject to a master netting arrangement.

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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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