Debt (Schedule of Short-term Debt) (Details) - USD ($) $ in Millions	Mar. 31, 2019	Dec. 31, 2018
Short-term Debt [Line Items]
Demand notes	$ 2,486	$ 2,477
Federal Home Loan Bank, advances	2,775	6,825
Securities sold under agreements to repurchase	854	685
Total short-term borrowings	6,115	9,987
Non-derivative cash collateral placed with counterparties associated with repurchase agreements		0
Non-derivative cash collateral received from counterparties associated with repurchase agreements	8	8
Non-derivative noncash collateral received from counterparties associated with repurchase agreements	3	4
Unsecured debt
Short-term Debt [Line Items]
Demand notes	2,486	2,477
Federal Home Loan Bank, advances	0	0
Securities sold under agreements to repurchase	0	0
Total short-term borrowings	2,486	2,477
Secured debt
Short-term Debt [Line Items]
Demand notes	0	0
Federal Home Loan Bank, advances	2,775	6,825
Securities sold under agreements to repurchase	854	685
Total short-term borrowings	3,629	$ 7,510
Maturity within 30 days \| Secured debt
Short-term Debt [Line Items]
Financial instruments sold under agreements to repurchase	513
Maturity within 31 to 60 days \| Secured debt
Short-term Debt [Line Items]
Financial instruments sold under agreements to repurchase	268
Maturity within 61 to 90 days \| Secured debt
Short-term Debt [Line Items]
Financial instruments sold under agreements to repurchase	73
US Treasury \| Secured debt
Short-term Debt [Line Items]
Financial instruments sold under agreements to repurchase	448
Agency mortgage-backed residential \| Secured debt
Short-term Debt [Line Items]
Financial instruments sold under agreements to repurchase	$ 406

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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- Definition

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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