Restructuring Activities - Summary of Changes in Liabilities for Restructuring Activities (Detail) - USD ($) $ in Millions		3 Months Ended	9 Months Ended
		Sep. 30, 2019	Sep. 30, 2019
Restructuring And Related Activities [Abstract]
Beginning Balance			$ 68
Reclassification of ASC 420 real estate restructuring to right-of -use asset	[1]		(22)
Charges		$ 3	45	[2]
Payments			(61)
Effect of foreign currency translation and other adjustments			(1)
Ending Balance		$ 29	$ 29

[1] Upon adoption of ASC 842, the real estate operating lease ASC 420 liabilities were reclassified and presented as a reduction of the related operating lease right-of-use asset.

[2] Excludes charges related to operating lease right-of-use assets of $7 million. Includes $6 million of adjustments related to changes in previous productivity initiatives.