Earning Per Common Share (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
Mar. 31, 2012	Mar. 31, 2011
Numerator (basic and diluted):
Income (loss) from continuing operations	$ 38	$ (41)
Allocation to unvested restricted stock awards	(1)	(1)
Income (loss) from continuing operations attributable to common shareholders	37	(42)
Loss from discontinued operations, net	(5)	(5)
Net income (loss) available to common shareholders	$ 32	$ (47)
Denominator
Basic common shares (based upon weighted average)	349	349
Add:
Contingent common shares
Stock option dilution	1
Diluted common shares	350	349

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Allocation to unvested restricted stock awards.

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(Loss) income from continuing operations attributable to common shareholders.

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This element represents the income or loss from continuing operations attributable to the parent which may also be defined as revenue less expenses and taxes from ongoing operations before extraordinary items but after deduction of those portions of income or loss from continuing operations that are allocable to noncontrolling interests, if any.

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Additional shares included in the calculation of diluted EPS as a result of the potentially dilutive effect of contingently issuable shares. Contingently issuable shares are those shares that are issuable for little or no cash contingent on certain conditions being met.

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Additional shares included in the calculation of diluted EPS as a result of the potentially dilutive effect of share based payment arrangements using the treasury stock method.

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Net income after adjustments for dividends on preferred stock (declared in the period) and/or cumulative preferred stock (accumulated for the period).

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