Income Taxes (Details 4) (USD $) In Millions	12 Months Ended
Dec. 31, 2010	Dec. 31, 2009	Dec. 31, 2008
Unrecognized Tax Benefits Rollforward (Table Amounts) [Abstract]
Unrecognized tax benefits at beginning of the year	$ 429	$ 416	$ 488
Additions based on tax positions related to the current year	19	12	5
Additions for tax positions of prior years	4	61	15
Statute expiration			(9)
Settlements	(326)	(60)	(83)
Net change in unrecognized tax benefits	(303)	13	(72)
Unrecognized tax benefits at end of the year	$ 126	$ 429	$ 416

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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The gross amount of unrecognized tax benefits (tax reductions recognized in financial reports but excluded from tax returns) pertaining to uncertain tax positions taken in tax returns as of the beginning balance sheet date, excluding amounts pertaining to examined tax returns.

+ References

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The gross amount of decreases in unrecognized tax benefits resulting from settlements with taxing authorities.

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The gross amount of increases in unrecognized tax benefits resulting from tax positions that have been or will be taken in the tax return for the current period, excluding amounts pertaining to examined tax returns.

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The gross amount of increases in unrecognized tax benefits resulting from tax positions taken in prior period tax returns, excluding amounts pertaining to examined tax returns.

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The net amount of all increases and decreases in unrecognized tax benefits for the period.

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The gross amount of decreases in unrecognized tax benefits resulting from lapses of the applicable statutes of limitations.

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