Income Taxes (Income Tax Expense (Benefit)) (Details) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2016	Mar. 31, 2015
Income Tax Contingency [Line Items]
Income tax (expense) benefit	$ (35)	$ 1
Effective Income Tax Rate, Continuing Operations	(21.00%)	9.00%
Income Tax Uncertainties [Abstract]
Unrecognized Tax Benefits	$ 57
Unrecognized Tax Benefits that Would Impact Effective Tax Rate	17
Unrecognized Tax Benefit Related to Deferred Tax Asset	40
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued	12
Minimum [Member]
Income Tax Contingency [Line Items]
Decrease in Unrecognized Tax Benefits is Reasonably Possible	0
Maximum [Member]
Income Tax Contingency [Line Items]
Decrease in Unrecognized Tax Benefits is Reasonably Possible	$ 18

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Amount of decrease reasonably possible in the next twelve months for the unrecognized tax benefit.

+ References

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
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Percentage of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

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Amount of unrecognized tax benefits.

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Amount accrued for interest on an underpayment of income taxes and penalties related to a tax position claimed or expected to be claimed in the tax return.

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The total amount of unrecognized tax benefits that, if recognized, would affect the effective tax rate.

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