Securities - Changes in Credit Loss (Details 4) (USD $) In Millions	3 Months Ended	9 Months Ended
Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
Changes in the credit loss component of credit-impaired debt securities, securities with no intent to sell [Abstract]
Balance, beginning of period	$ 675	$ 640	$ 632	$ 578
Additions:
Newly credit-impaired securities	0	0	4	0
Increase in losses on previously credit-impaired securities	0	0	0	94
Losses reclassified from other comprehensive income on previously credit-impaired securities	15	0	54	6
Reductions:
Sales of credit-impaired securities	0	(8)	0	(31)
Impact of new accounting guidance related to VIEs	0	0	0	(15)
Balance, end of period	$ 690	$ 632	$ 690	$ 632

Additions Abstract.

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Changes in the credit loss component of credit-impaired debt securities, Securities Not Held For Sale.

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Reductions Abstract.

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Amount of the effect of a change in accounting principle on net income.

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This item represents an increase to the cumulative amount of credit losses recognized in earnings for an other than temporary impairment (OTTI) of a debt security held for which a previous OTTI was recognized and the investor does not intend to sell the debt security and it is not more likely than not that the investor will be required to sell the debt security before recovery of its amortized cost basis.

+ References

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This item represents an increase to the cumulative amount of credit losses recognized in earnings for an other than temporary impairment (OTTI) of a debt security held for which no such other than temporary impairment (OTTI) was previously recognized.

+ References

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The cumulative amount of credit losses recognized in earnings related to debt securities held for which a portion of an other than temporary impairment (OTTI) was recognized in other comprehensive income (a component of shareholders' equity).

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This item represents reductions in the amount of cumulative losses recognized in earnings for other than temporary impairments (OTTI) for which a portion of the impairment had been recognized in other comprehensive income (a component of shareholders' equity) due to a change in status of the impaired security because of a change in the entity's intent to either sell the impaired security or it has become more likely than not that the entity will be required to sell the security before recovery of its cost basis.

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This item represents reductions in the cumulative amount of credit losses recognized in earnings for an other than temporary impairment (OTTI) of a debt security because of the sale of impaired securities during the period.

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