Investment Securities (Gains And Losses Related To Investment Securities) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
Mar. 31, 2012	Mar. 31, 2011
Investments, All Other Investments [Abstract]
Gross realized gains from sales of available-for-sale securities	$ 19	$ 7
Gross realized losses from sales of available-for-sale securities	0	(3)
Gross losses from other-than-temporary impairment	(25)	(35)
Losses not related to credit	17	24
Gains (Losses) related to investment securities, net	11	(7)
Impairment associated with expected credit losses	(4)	(5)
Impairment associated with adverse changes in timing of expected future cash flows	(4)	(6)
Net impairment losses	$ (8)	$ (11)

The amount by which the fair value of an investment is less than the amortized cost basis or carrying amount of that investment at the balance sheet date and the decline in fair value is deemed to be other than temporary, before considering whether or not such amount is recognized in earnings or other comprehensive income.

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Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

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Reference 5: http://www.xbrl.org/2003/role/presentationRef

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+ Details

- Definition

This item represents the net total realized and unrealized gain (loss) included in earnings for the period as a result of selling or holding marketable securities categorized as trading, available-for-sale, or held-to-maturity, including the unrealized holding gain (loss) of held-to-maturity securities transferred to the trading security category and the cumulative unrealized gain (loss) which was included in other comprehensive income (a separate component of shareholders' equity) for available-for-sale securities transferred to trading securities during the period. Additionally, this item would include any losses recognized for other than temporary impairments (OTTI) of the subject investments in debt and equity securities.

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