Loans and Loans Held for Sale - Summary of Changes in Loans Held for Sale (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended	9 Months Ended
Sep. 30, 2013	Dec. 31, 2012	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Loans Receivables [Abstract]
Balance at beginning of the period	$ 402	$ 628	$ 656	$ 599
New originations	1,467	1,686	1,280
Transfers from held to maturity, net	15	38	13
Loan sales	(1,181)	(1,747)	(1,311)
Loan draws (payments), net	(4)	(4)	(9)	(3,779)	(3,507)
Transfers to OREO / valuation adjustments		(2)	(1)
Balance at end of period	$ 699	$ 599	$ 628	$ 699	$ 628

The aggregate carrying amount of loans receivable that will be sold to other entities. Includes mortgage and all other loans (collectively, loans) not classified as held for investment. Such loans are stated at the lower of cost or market, or elected fair value. Mortgage loans exclude mortgage-backed securities which are considered a debt security (other loan).

Reference 1: http://www.xbrl.org/2003/role/presentationRef

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-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

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-Name Statement of Financial Accounting Standard (FAS)

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+ Details

- Definition

The aggregate cash outflow used to purchase all loans that are held with the intention to resell in the near future.

+ References+ Details