Restructuring, Impairment and Related Charges - Summary of Restructuring Activity (Details) - Fiscal 2019 Initiatives - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Restructuring Reserve [Roll Forward]
Beginning balance			$ 150
Restructuring, impairment and related charges	$ 43	$ 75	66	$ 144
Non-cash charges			(12)
Cash Payments			(50)
Other			(13)
Ending balance	141		141
Operating Segments | U.S. Pharmaceutical and Specialty Solutions
Restructuring Reserve [Roll Forward]
Beginning balance			31
Restructuring, impairment and related charges	2	5	1	13
Non-cash charges			0
Cash Payments			(3)
Other			0
Ending balance	29		29
Operating Segments | European Pharmaceutical Solutions
Restructuring Reserve [Roll Forward]
Beginning balance			38
Restructuring, impairment and related charges	10		13
Non-cash charges			(6)
Cash Payments			(10)
Other			(1)
Ending balance	34		34
Operating Segments | Medical-Surgical Solutions
Restructuring Reserve [Roll Forward]
Beginning balance			15
Restructuring, impairment and related charges	3	6	6	18
Non-cash charges			(1)
Cash Payments			(1)
Other			0
Ending balance	19		19
Operating Segments | Other
Restructuring Reserve [Roll Forward]
Beginning balance			29
Restructuring, impairment and related charges	1	42	2	80
Non-cash charges			0
Cash Payments			(14)
Other			(7)
Ending balance	10		10
Corporate
Restructuring Reserve [Roll Forward]
Beginning balance			37
Restructuring, impairment and related charges	27	$ 22	44	$ 33
Non-cash charges			(5)
Cash Payments			(22)
Other			(5)
Ending balance	$ 49		$ 49