Investment Securities (Details 3) (USD $) In Millions, unless otherwise specified	Sep. 30, 2013
Available For Sale Securities Debt Maturities Amortized Cost [Abstract]
Due within 1 year	$ 571
Due after 1 year but within 5 years	337
Due after 5 years but within 10 years	159
Due after 10 years	3,838
Total	4,905
Estimated Fair Value
Estimated Fair Value, Due within 1 year	571
Estimated Fair Value, Due after 1 year but within 5 years	345
Estimated Fair Value, Due after 5 years but within 10 years	166
Estimated Fair Value, Due after 10 years	3,839
Total	$ 4,921

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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Amount of available-for-sale debt securities at cost, net of adjustments, maturing in the second fiscal year through the fifth 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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Amount of available-for-sale debt securities at fair value maturing in the second fiscal year through the fifth fiscal year following the latest fiscal year.

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Amount of available-for-sale debt securities at fair value maturing after the tenth fiscal year following the latest fiscal year.

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Amount of available-for-sale debt securities at cost, net of adjustments, maturing in the next 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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Amount of debt securities categorized neither as held-to-maturity nor trading.

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