Income Taxes - Uncertain Tax Positions (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Beginning balance	$ 293	$ 261	$ 220
Increases to tax positions related to the current year	12	24	35
Increases to tax positions related to prior years	5	2	4
Decreases to tax positions related to prior years	0	0	(1)
Reductions due to lapsed statute of limitations	(2)	(2)	(3)
Settlements during current year	(11)	0	(1)
Interest and penalties	8	8	7
Ending balance	$ 305	$ 293	$ 261

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

No definition available.

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- Definition

Amount of unrecognized tax benefits.

+ References

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Amount of decrease in unrecognized tax benefits resulting from tax positions taken in prior period tax returns.

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Amount of expense for interest on an underpayment of income taxes and penalties related to a tax position claimed or expected to be claimed in the tax return.

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Amount of increase in unrecognized tax benefits resulting from tax positions that have been or will be taken in current period tax return.

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