Restructuring and Other Related Charges (Summary Of Changes To Restructuring-Related Liabilities) (Detail) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2021	Mar. 31, 2020
Restructuring Reserve [Roll Forward]
Balance as of January 1, 2020	$ 9
Restructuring expenses	20	$ 44
Balance as of March 31, 2021	7
Americas
Restructuring Reserve [Roll Forward]
Balance as of January 1, 2020	3
Balance as of March 31, 2021	1
International
Restructuring Reserve [Roll Forward]
Balance as of January 1, 2020	6
Balance as of March 31, 2021	6
T21
Restructuring Reserve [Roll Forward]
Restructuring expenses	7
Restructuring payment/utilization	(5)
T21 \| Americas
Restructuring Reserve [Roll Forward]
Restructuring expenses	1
Restructuring payment/utilization	(1)
T21 \| International
Restructuring Reserve [Roll Forward]
Restructuring expenses	6
Restructuring payment/utilization	(4)
2020 Optimization Plan
Restructuring Reserve [Roll Forward]
Restructuring payment/utilization	(4)
2020 Optimization Plan \| Americas
Restructuring Reserve [Roll Forward]
Restructuring payment/utilization	(2)
2020 Optimization Plan \| International
Restructuring Reserve [Roll Forward]
Restructuring payment/utilization	(2)
Personnel
Restructuring Reserve [Roll Forward]
Balance as of January 1, 2020	4
Balance as of March 31, 2021	3
Personnel \| T21
Restructuring Reserve [Roll Forward]
Restructuring expenses	5
Restructuring payment/utilization	(3)
Personnel \| 2020 Optimization Plan
Restructuring Reserve [Roll Forward]
Restructuring payment/utilization	(3)
Facility Related
Restructuring Reserve [Roll Forward]
Balance as of January 1, 2020	2
Balance as of March 31, 2021	2
Facility Related \| T21
Restructuring Reserve [Roll Forward]
Restructuring expenses	2
Restructuring payment/utilization	(2)
Facility Related \| 2020 Optimization Plan
Restructuring Reserve [Roll Forward]
Restructuring payment/utilization	0
Other
Restructuring Reserve [Roll Forward]
Balance as of January 1, 2020	3
Balance as of March 31, 2021	2
Other \| T21
Restructuring Reserve [Roll Forward]
Restructuring expenses	0
Restructuring payment/utilization	0
Other \| 2020 Optimization Plan
Restructuring Reserve [Roll Forward]
Restructuring payment/utilization	$ (1)

Amount of cash payments made as the result of exit or disposal activities. Excludes payments associated with a discontinued operation or an asset retirement obligation.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 420
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (b)(2)
-URI http://asc.fasb.org/extlink&oid=6394359&loc=d3e17939-110869

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 17
-Subparagraph (f)
-URI http://asc.fasb.org/extlink&oid=121586364&loc=d3e3367-108585

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- Definition

Amount of expenses associated with exit or disposal activities pursuant to an authorized plan. Excludes expenses related to a discontinued operation or an asset retirement obligation.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 420
-SubTopic 10
-Section S99
-Paragraph 1
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-Name Accounting Standards Codification
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Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 420
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-Section S99
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-URI http://asc.fasb.org/extlink&oid=115931487&loc=d3e140904-122747

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- Definition

Carrying amount (including both current and noncurrent portions of the accrual) as of the balance sheet date pertaining to a specified type of cost associated with exit from or disposal of business activities or restructuring pursuant to a duly authorized plan.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 420
-SubTopic 10
-Section 50
-Paragraph 1
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- Definition

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

+ References

No definition available.

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