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Income Taxes - Narrative (Details) - USD ($) $ / shares in Units, $ in Millions | 3 Months Ended | 12 Months Ended
--- | --- | ---
Dec. 31, 2017 | Dec. 31, 2018 | Dec. 31, 2017 | Dec. 31, 2016
Operating Loss Carryforwards [Line Items] |  |  |  |
Total provision (benefit) from income taxes | $ 345 |  |  |
Transition tax payable | 264 | $ 240 | $ 264 |
Estimated transition tax |  |  | 264 |
Estimated tax expense for the re-measurement of deferred tax assets and liabilities |  |  | $ 86 |
Statutory tax rate |  | 19.00% | 19.30% | 20.00%
Decrease in valuation allowance |  | $ 35 |  |
Benefit realized from tax holiday granted |  | $ 77 | $ 45 | $ 46
Earnings per share impact of tax holiday (in dollars per share) |  | $ 0.31 | $ 0.17 | $ 0.17
Unrecognized tax benefits that would impact effective tax rate | 219 | $ 228 | $ 219 | $ 240
Accrued potential interest and penalties |  | 22 | 11 | 15
Liability recorded for interest and penalties | 55 | 77 | 55 | $ 48
Unremitted earnings | $ 39 | $ 30 | $ 39 |

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- Definition Amount of deferred tax liability attributable to taxable temporary differences from undistributed earnings of subsidiaries and other recognized entities not within the country of domicile of the entity. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 6 -URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32621-109319 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 8 -URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32632-109319 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 25 -Paragraph 20 -URI http://asc.fasb.org/extlink&oid=115928272&loc=d3e28680-109314 + Details
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