Short-Term Borrowings - Overnight maturity (Details) $ in Millions	Dec. 31, 2017 USD ($)
U.S. Government Securities Sold
Short-term Debt [Line Items]
Amortized cost of overnight maturity	$ 2,928
Fair value of overnight maturity	2,899
Repurchase Agreements
Short-term Debt [Line Items]
Amortized cost of overnight maturity	$ 2,842

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.

No definition available.

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