Income Taxes - Summary of Activity Related to Unrecognized Tax Benefits (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	$ 108	$ 94	$ 71
Decrease related to agreements with tax authorities	(17)	(40)	(14)
Increase related to tax positions taken during current year	13	12	26
Increase related to tax positions taken during prior years	49	44	11
Decreases related to a lapse of the applicable statute of limitations	(4)	(2)	0
Ending balance	$ 149	$ 108	$ 94

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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-Publisher FASB
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- Definition

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

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

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

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