Investment Securities (Details 4) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012
Available For Sale Securities Debt Maturities Amortized Cost [Abstract]
Due within 1 year	$ 318
Due after 1 year but within 5 years	255
Due after 5 years but within 10 years	204
Due after 10 years	4,253
Total	5,030
Estimated Fair Value
Estimated Fair Value, Due within 1 year	319
Estimated Fair Value, Due after 1 year but within 5 years	264
Estimated Fair Value, Due after 5 years but within 10 years	220
Estimated Fair Value, Due after 10 years	4,464
Total	$ 5,267

Amount of available-for-sale debt securities at cost, net of adjustments, maturing in the sixth fiscal year through the tenth fiscal year following the latest fiscal year. Adjustments include, but are not limited to, accretion, amortization, collection of cash, previous other-than-temporary impairments (OTTI) recognized in earnings (less any cumulative-effect adjustments, as defined) and fair value hedge accounting adjustments.

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