Business Restructuring Charges - Summary of Restructuring Accrual Activity (Detail) $ in Millions	3 Months Ended
	Dec. 31, 2017 USD ($)
CR Bard Inc [Member]
Restructuring Reserve [Roll Forward]
Balance at September 30, 2017	$ 0
Charged to expense	217
Cash payments	(26)
Non-cash settlements	(75)
Other adjustments	0
Balance at December 31, 2017	117
CR Bard Inc [Member] | Employee Termination
Restructuring Reserve [Roll Forward]
Balance at September 30, 2017	0
Charged to expense	142
Cash payments	(26)
Non-cash settlements	0
Other adjustments	0
Balance at December 31, 2017	117
CR Bard Inc [Member] | Other Restructuring [Member]
Restructuring Reserve [Roll Forward]
Balance at September 30, 2017	0
Charged to expense	75
Cash payments	0
Non-cash settlements	(75)
Other adjustments	0
Balance at December 31, 2017	0
CareFusion and Other Initiatives [Member]
Restructuring Reserve [Roll Forward]
Balance at September 30, 2017	55
Charged to expense	19
Cash payments	(25)
Non-cash settlements	0
Other adjustments	(2)
Balance at December 31, 2017	50
CareFusion and Other Initiatives [Member] | Employee Termination
Restructuring Reserve [Roll Forward]
Balance at September 30, 2017	49
Charged to expense	9
Cash payments	(16)
Non-cash settlements	0
Other adjustments	0
Balance at December 31, 2017	42
CareFusion and Other Initiatives [Member] | Other Restructuring [Member]
Restructuring Reserve [Roll Forward]
Balance at September 30, 2017	6
Charged to expense	10
Cash payments	(9)
Non-cash settlements	0
Other adjustments	(2)
Balance at December 31, 2017	$ 8