Income Taxes (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended	9 Months Ended
Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
Income Taxes
The effective tax rate	19.60%	81.70%	25.30%	46.00%
Difference in effective income tax rate		116.70%
U.S. federal statutory rate	35.00%	35.00%	35.00%	35.00%
Discrete income tax benefit	$ 15.0
Discrete income tax benefit (charge)		41		(79)
Discrete income tax charge based on settlement discussions of several matters with international taxing authorities				19
Income tax impact for operational losses related to certain foreign jurisdictions that are excluded from the estimated annual effective tax rate calculation		8
Net discrete tax benefits for various other items		19		9
Discrete income tax benefit related to a Canadian provincial tax law change				$ 24

Discrete Income Tax Charge For A Change In The Anticipated Structure Of Potential Sale

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A ratio calculated by dividing the reported amount of income tax expense attributable to continuing operations for the period by GAAP-basis pretax income from continuing operations.

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The domestic federal statutory tax rate applicable under enacted tax laws to the Company's pretax income from continuing operations for the period. The "statutory" tax rate is the regular tax rate if there are alternative tax systems.

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The portion of the difference between the effective income tax rate and domestic federal statutory income tax rate attributable to domestic income tax settlements during the period.

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The portion of the difference between total income tax expense or benefit as reported in the Income Statement and the expected income tax expense or benefit computed by applying the domestic federal statutory income tax rates to pretax income from continuing operations, that is attributable to changes in the income tax rates under enacted tax laws in the period.

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The sum of other amounts reflected in the reconciliation of the statutory tax provision (benefit) to the actual tax provision (benefit).

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The portion of the difference between total income tax expense or benefit as reported in the Income Statement and the expected income tax expense or benefit computed by applying the domestic federal statutory income tax rates to pretax income from continuing operations attributable to changes in foreign income tax contingencies, whether recorded or adjusted, during the period.

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The portion of the difference between total income tax expense or benefit as reported in the Income Statement and the expected income tax expense or benefit computed by applying the domestic federal statutory income tax rates to pretax income from continuing operations attributable to foreign income tax settlements for the period.

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Reflects the effects of adjustments of previously recorded tax expense, significant settlements of income tax disputes, and unusual tax positions or infrequent actions taken by the entity, including tax assessment reversal, IRS tax settlement and unusual repatriation of foreign earnings.

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