(Schedule of Unrecognized Tax Benefits Rollforward) (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Balance at January 1	$ (220)	$ (188)	$ (98)
(Additions) reductions for tax positions related to current year	(5)	(7)	(54)
(Additions) for tax positions related to prior years	(6)	(37)	(40)
Reductions for tax positions related to prior years	5	5	4
Settlements	31	2	6
Expiration of statutes of limitations	3	2	1
Currency translation adjustment	3	3	(7)
Balance at December 31	$ (189)	$ (220)	$ (188)

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Amount of unrecognized tax benefits.

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Amount of decrease in unrecognized tax benefits resulting from foreign currency translation.

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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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