Income Taxes (Income Tax Contingencies) (Details) - USD ($) $ in Millions |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2016 |
Dec. 31, 2015 |
Dec. 31, 2014 |
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| Income Tax Disclosure [Abstract] | |||
| Balance, beginning of period | $ (58) | $ (56) | $ (68) |
| Increases related to prior year tax positions | 0 | 0 | (4) |
| Decreases related to prior year tax positions | 1 | 3 | 8 |
| Unrecognized Tax Benefits, Increase Resulting from Current Period Tax Positions | (2) | (5) | 0 |
| Settlements | 0 | 0 | 8 |
| Balance, end of period | $ (59) | $ (58) | $ (56) |
| X | ||||||||||
- References No definition available.
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- Definition Amount of unrecognized tax benefits. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
- Definition Amount of decrease in unrecognized tax benefits resulting from tax positions taken in prior period tax returns. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
- Definition Amount of decrease in unrecognized tax benefits resulting from settlements with taxing authorities. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
- Definition Amount of increase in unrecognized tax benefits resulting from tax positions that have been or will be taken in current period tax return. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
- Definition Amount of increase in unrecognized tax benefits resulting from tax positions taken in prior period tax returns. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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