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Investments (Investment Securities Whose Book Value Exceeded Market Value By More Than 5%) (Details) (USD $) In Millions, unless otherwise specified | 9 Months Ended
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Sep. 30, 2011
Schedule of Trading Securities and Other Trading Assets [Line Items] |
Number of Securities | 215
Book Value | $ 4,255
Fair Value | 3,426
5% To 15% [Member] |
Schedule of Trading Securities and Other Trading Assets [Line Items] |
Number of Securities | 52
Book Value | 2,358
Fair Value | 2,136
Percentage Book Value Exceeded Market Value, Minimum | 5.00%
Percentage Book Value Exceeded Market Value, Maximum | 15.00%
16% To 25% [Member] |
Schedule of Trading Securities and Other Trading Assets [Line Items] |
Number of Securities | 51
Book Value | 1,096
Fair Value | 860
Percentage Book Value Exceeded Market Value, Minimum | 16.00%
Percentage Book Value Exceeded Market Value, Maximum | 25.00%
26% To 50% [Member] |
Schedule of Trading Securities and Other Trading Assets [Line Items] |
Number of Securities | 79
Book Value | 556
Fair Value | 370
Percentage Book Value Exceeded Market Value, Minimum | 26.00%
Percentage Book Value Exceeded Market Value, Maximum | 50.00%
Greater Than 50% [Member] |
Schedule of Trading Securities and Other Trading Assets [Line Items] |
Number of Securities | 33
Book Value | 245
Fair Value | $ 60
Percentage Book Value Exceeded Market Value, Minimum | 50.00%

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- Definition Disclosure regarding factors used to determine that the impairment of securities not categorized as trading securities (hence equal to available for sale and held to maturity securities) where cost exceeds fair value. This item contains disclosure of the number of investment positions in the investments determined to be temporarily impaired. + Details
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- Definition Investments Securities In Unrealized Loss Position For Continuous Twelve Month Period or Longer At Fair Value + Details
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- Definition Investments Securities In Unrealized Loss Position For Continuous Twelve Month Period or Longer Book Value + Details
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- Definition Percentage Book Value Exceeded Market Value, Maximum + Details
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- Definition Percentage Book Value Exceeded Market Value, Minimum + Details
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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + Details
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