Income Taxes - Income Before Income Taxes (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Tax Disclosure [Abstract]
U.S. income before tax	$ 881	$ 632	$ 906
Foreign income (loss) before tax	197	121	(366)
Income from continuing operations before income taxes	$ 1,078	$ 753	$ 540

The portion of earnings or loss from continuing operations before income taxes that is attributable to domestic operations.

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-Name Accounting Standards Codification
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- Definition

Amount of income (loss) from continuing operations, including income (loss) from equity method investments, before deduction of income tax expense (benefit), and income (loss) attributable to noncontrolling interest.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
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-Publisher FASB
-Name Accounting Standards Codification
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- Definition

The portion of earnings or loss from continuing operations before income taxes that is attributable to foreign operations, which is defined as Income or Loss generated from operations located outside the entity's country of domicile.

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