Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2019	Mar. 31, 2018
Income Tax Disclosure [Abstract]
Effective income tax rate	16.30%	24.30%
Tax Adjustments, Settlements, and Unusual Provisions		$ 49
Decrease in Unrecognized Tax Benefits/Tax Expenses As a Result of Settlements with Taxing Authoritiess	$ 119

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

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Amount of increase (decrease) to previously recorded tax expense. Includes, but is not limited to, significant settlements of income tax disputes, and unusual tax positions or infrequent actions taken by the entity, including tax assessment reversal, and IRS tax settlement.

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Amount of decrease in unrecognized tax benefits resulting from settlements with taxing authorities.

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