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Business Developments, Risks And Uncertainties, And Liquidity (Change In Credit Spreads (Asset/Liability Products Business) (Detail) (USD $) In Millions, unless otherwise specified	Sep. 30, 2012
200 Basis Point Decrease [Member]
Business Acquisition [Line Items]
Estimated change in fair value	$ 149
50 Basis Point Decrease [Member]
Business Acquisition [Line Items]
Estimated change in fair value	41
50 Basis Point Increase [Member]
Business Acquisition [Line Items]
Estimated change in fair value	(37)
200 Basis Point Increase [Member]
Business Acquisition [Line Items]
Estimated change in fair value	$ (130)

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- Definition

Estimated change in fair value

+ References

No definition available.

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