Components of Other Short-Term Borrowings (Detail) - USD ($) $ in Millions	Sep. 30, 2015	Dec. 31, 2014
Short Term Debt [Table] [Abstract]
FHLB advances	$ 3,450
Securities sold under repurchase agreements	814	$ 995
Derivative collateral	638	561
OtherBorrowings	2
Total other short-term borrowings	$ 4,904	$ 1,556

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Amount of obligation to return cash collateral under master netting arrangements that have not been offset against derivative assets.

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Amount of advances from the Federal Home Loan Bank (FHLB).

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The carrying amount as of the balance sheet date for the aggregate of other miscellaneous borrowings owed by the reporting entity.

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Sum of the carrying amounts at the balance sheet date of short-term borrowings not otherwise specified in the taxonomy having initial terms less than one year or the normal operating cycle, if longer.

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Amount, after the 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 not subject to a master netting arrangement and not elected to be offset.

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