Restructuring (Summary Of Changes To Restructuring-Related Liabilities) (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Restructuring Reserve [Roll Forward]
Balance as of January 1, 2016			$ 2
Restructuring expense	$ (22)	$ (4)	(66)	$ (14)
Balance as of September 30, 2019	5		5
Americas
Restructuring Reserve [Roll Forward]
Balance as of January 1, 2016			0
Balance as of September 30, 2019	2		2
International [Member]
Restructuring Reserve [Roll Forward]
Balance as of January 1, 2016			2
Balance as of September 30, 2019	3		3
Workforce Restructuring [Member]
Restructuring Reserve [Roll Forward]
Payment for Restructuring			(1)
Workforce Restructuring [Member] | Americas
Restructuring Reserve [Roll Forward]
Payment for Restructuring			0
Workforce Restructuring [Member] | International [Member]
Restructuring Reserve [Roll Forward]
Payment for Restructuring			(1)
Brazil Restructuring [Member]
Restructuring Reserve [Roll Forward]
Restructuring expense	(6)		(6)
Payment for Restructuring			(4)
Brazil Restructuring [Member] | Americas
Restructuring Reserve [Roll Forward]
Restructuring expense			(6)
Payment for Restructuring			(4)
Brazil Restructuring [Member] | International [Member]
Restructuring Reserve [Roll Forward]
Restructuring expense			0
Payment for Restructuring			0
T19 Restructuring [Member]
Restructuring Reserve [Roll Forward]
Restructuring expense			(45)
Payment for Restructuring			(43)
T19 Restructuring [Member] | Americas
Restructuring Reserve [Roll Forward]
Restructuring expense			(34)
Payment for Restructuring			(34)
T19 Restructuring [Member] | International [Member]
Restructuring Reserve [Roll Forward]
Restructuring expense			(11)
Payment for Restructuring			(9)
Personnel
Restructuring Reserve [Roll Forward]
Balance as of January 1, 2016			1
Balance as of September 30, 2019	2		2
Personnel | Workforce Restructuring [Member]
Restructuring Reserve [Roll Forward]
Payment for Restructuring			(1)
Personnel | Brazil Restructuring [Member]
Restructuring Reserve [Roll Forward]
Restructuring expense			(1)
Payment for Restructuring			0
Personnel | T19 Restructuring [Member]
Restructuring Reserve [Roll Forward]
Restructuring expense			(16)
Payment for Restructuring			(15)
Facility Closing [Member]
Restructuring Reserve [Roll Forward]
Balance as of January 1, 2016			0
Balance as of September 30, 2019	1		1
Facility Closing [Member] | Workforce Restructuring [Member]
Restructuring Reserve [Roll Forward]
Payment for Restructuring			0
Facility Closing [Member] | Brazil Restructuring [Member]
Restructuring Reserve [Roll Forward]
Restructuring expense			(1)
Payment for Restructuring			0
Facility Closing [Member] | T19 Restructuring [Member]
Restructuring Reserve [Roll Forward]
Restructuring expense			0
Payment for Restructuring			0
Other Restructuring [Member]
Restructuring Reserve [Roll Forward]
Balance as of January 1, 2016			1
Balance as of September 30, 2019	$ 2		2
Other Restructuring [Member] | Workforce Restructuring [Member]
Restructuring Reserve [Roll Forward]
Payment for Restructuring			0
Other Restructuring [Member] | Brazil Restructuring [Member]
Restructuring Reserve [Roll Forward]
Restructuring expense			(4)
Payment for Restructuring			(4)
Other Restructuring [Member] | T19 Restructuring [Member]
Restructuring Reserve [Roll Forward]
Restructuring expense			(29)
Payment for Restructuring			$ (28)