Fair Value Measurements (Schedule Of Maturities On Debt Securities) (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2012
Fair Value Measurements [Abstract]
Less than 1 year	$ 29
1-5 years	408
5-10 years	264
More than 10 years	389
Total maturities of debt securities	$ 1,090

This item represents the fair value of debt securities which are expected to mature after five years and through ten years from the balance sheet date and which are categorized neither as held-to-maturity nor trading securities.

+ References+ Details

This item represents the fair value of debt securities which are expected to mature after one year and through five years from the balance sheet date and which are categorized neither as held-to-maturity nor trading securities.

+ References+ Details

- Definition

This item represents the fair value of debt securities which are expected to mature within one year of the balance sheet date and which are categorized neither as held-to-maturity nor trading securities.

+ References+ Details

- Definition

For an unclassified balance sheet, total of debt securities categorized neither as held-to-maturity nor trading.

+ References

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Reference 6: http://www.xbrl.org/2003/role/presentationRef

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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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+ Details