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Fair Value Of Financial Instruments (Changes In Fair Value Included In Company's Consolidated Statements Of Operations) (Detail) (USD $) In Millions, unless otherwise specified | 3 Months Ended | 9 Months Ended
--- | --- | ---
Sep. 30, 2012 | Sep. 30, 2011 | Sep. 30, 2012 | Sep. 30, 2011
Loan Repurchase Commitments [Member] |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |
Net gains (losses) on financial instruments at fair value and foreign exchange | $ 19 | $ 33 | $ 62 | $ 103
Fixed-Maturity Securities Held At Fair Value [Member] |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |
Net gains (losses) on financial instruments at fair value and foreign exchange | 21 | (286) | (36) | (338)
Residential Mortgage Loans [Member] |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |
Net gains (losses) on financial instruments at fair value and foreign exchange | (4) | (65) | (103) | 65
Other Loans [Member] |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |
Net gains (losses) on financial instruments at fair value and foreign exchange | (7) | (37) | (48) | (30)
Other Assets [Member] |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |
Net gains (losses) on financial instruments at fair value and foreign exchange |  | (162) |  | (184)
Long-term Debt [Member] |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |
Net gains (losses) on financial instruments at fair value and foreign exchange | $ 12 | $ 481 | $ 140 | $ 367

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- Definition Change in the fair value of and realized gains and losses on financial instruments and foreign exchange included in earnings. + References No definition available. + Details
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