Income Taxes - Schedule of Domestic and Foreign Income Before Income Taxes (Detail) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
U.S. income before tax	$ 350	$ 498	$ 279
Foreign income before tax	1	2	6
Income before income taxes	$ 351	$ 500	$ 285

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
-Topic 235
-SubTopic 10
-Section S99
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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
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-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
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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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