Restructuring - Summary of Amounts Recorded for Restructuring Plans (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Restructuring Cost and Reserve [Line Items]
Restructuring reserves, beginning balance	$ 102	$ 14
Expense, net of reversals	63	63
Acquisitions		80
Payments	(81)	(50)
Foreign currency translation and other		(5)
Restructuring reserves, ending balance	84	102
Severance and Related Costs [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring reserves, beginning balance	99	12
Expense, net of reversals	59	60
Acquisitions		80
Payments	(77)	(48)
Foreign currency translation and other	(1)	(5)
Restructuring reserves, ending balance	80	99
Exit Costs [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring reserves, beginning balance	3	2
Expense, net of reversals	4	3
Payments	(4)	(2)
Foreign currency translation and other	1
Restructuring reserves, ending balance	$ 4	$ 3