v3.8.0.1

Income Taxes (Unrecognized Tax Benefits) (Details) - USD ($) $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2017 | Dec. 31, 2016 | Dec. 31, 2015
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward] |  |  |
Amount | $ 26 | $ 6 | $ 6
Increases in unrecognized tax benefits—prior years | 11 | 10 | 0
(Decreases) in unrecognized tax benefits—prior years | (5) | 0 | 0
Increases in unrecognized tax benefits—current year | 14 | 10 | 0
(Decreases) in unrecognized tax benefits—current year | 0 | 0 | 0
Settlements with taxing authorities | (1) | 0 | 0
Amount | 45 | 26 | 6
Unrecognized tax benefits that, if recognized, would favorably impact the effective rate | $ 45 | $ 26 | $ 6

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- Definition A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period. + References No definition available. + Details
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- Definition Amount of unrecognized tax benefits. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 15A -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=84230637&loc=SL6600010-109319 + Details
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- Definition Amount of decrease in unrecognized tax benefits resulting from tax positions that have been or will be taken in current period tax return. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 15A -Subparagraph (a)(2) -URI http://asc.fasb.org/extlink&oid=84230637&loc=SL6600010-109319 + Details
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