Income Taxes (Impact of Accounting for the Enactment of the Tax Act) (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Revaluation of deferred tax asset balances	$ 1
Revaluation of deferred tax liability balances		$ (746)
One time transition tax	5	57
Tax Cuts and Jobs Act, Income Tax Expense (Benefit)	$ 6	$ (689)

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- Definition

Amount of income tax expense for remeasurement of deferred tax asset from change in tax rate pursuant to Tax Cuts and Jobs Act.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 9
-URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32639-109319

+ Details

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- Definition

Amount of income tax benefit for remeasurement of deferred tax liability from change in tax rate pursuant to Tax Cuts and Jobs Act.

+ References

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- Definition

Amount of income tax expense (benefit) from effect of Tax Cuts and Jobs Act.

+ References

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- Definition

Amount of income tax expense from transition tax on accumulated earnings of controlled foreign corporation deemed repatriated pursuant to Tax Cuts and Jobs Act.

+ References

+ Details

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