Percentage of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

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Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

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Amount of interest expense accrued for an underpayment of income taxes.

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Amount of decrease in unrecognized tax benefits resulting from lapses of applicable statutes of limitations.

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The total amount of unrecognized tax benefits that, if recognized, would affect the effective tax rate.

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Income Taxes (Textuals) (Details) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
Income Taxes (Textuals) (Details) - USD ($) $ in Millions	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Income tax provision	$ 15	$ 16
Effective tax rate	16.60%	17.10%
Unrecognized tax benefits	$ 132			$ 136
Interest accrued for unrecognized tax benefits	$ 8
Scenario, Forecast
Income Tax Contingency [Line Items]
Reduction from statute of limitations			$ 8