XML 248 R81.htm IDEA: XBRL DOCUMENT

Securities - Additional Information (Detail) (USD $)	6 Months Ended
Securities - Additional Information (Detail) (USD $)	Jun. 30, 2013 MortgageLoan	Jun. 30, 2012
Schedule of Available-for-sale Securities [Line Items]
Gross unrealized loss attributable to collateralized mortgage obligations	$ 113,000,000
Number of fixed rate collateralized mortgage obligations	53
Weighted-average maturity collateralized mortgage, in years	4 years 2 months 12 days
Gross unrealized loss attributable to mortgage-backed securities	166,000,000	1,000,000
Weighted-average maturity mortgage-backed securities, in years	4 years 10 months 24 days
Pledged available for sale and held-to-maturity securities	12,000,000,000
Other Mortgage-Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross unrealized loss attributable to mortgage-backed securities	$ 3,000,000

Carrying amount as of the balance sheet date of loans that have been pledged as collateral for borrowings. If the secured party has the right by contract or custom to sell or re-pledge the collateral, then the debtor reclassifies that asset and report that asset in its statement of financial position separately from other assets not so encumbered.

+ References+ Details