Restructuring, Impairment and Related Charges - Summary of Activity Related to Restructuring Liability (Details) - USD ($) $ in Millions	12 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Other
Cost Alignment Plan
Restructuring charges recognized		$ 91
Strategic Growth Initiative Plan
Cost Alignment Plan
Beginning balance	$ 150
Restructuring charges recognized	131	331
Non-cash charges	(16)
Cash payments	(136)
Other	(19)
Ending balance	110	150
Strategic Growth Initiative Plan | Operating Segments | U.S. Pharmaceutical and Specialty Solutions
Cost Alignment Plan
Beginning balance	31
Restructuring charges recognized	3	63
Non-cash charges	0
Cash payments	(13)
Other	1
Ending balance	22	31
Strategic Growth Initiative Plan | Operating Segments | European Pharmaceutical Solutions
Cost Alignment Plan
Beginning balance	38
Restructuring charges recognized	17	41
Non-cash charges	(5)
Cash payments	(26)
Other	0
Ending balance	24	38
Strategic Growth Initiative Plan | Operating Segments | Medical-Surgical Solutions
Cost Alignment Plan
Beginning balance	15
Restructuring charges recognized	22	42
Non-cash charges	(1)
Cash payments	(16)
Other	(2)
Ending balance	18	15
Strategic Growth Initiative Plan | Operating Segments | Other
Cost Alignment Plan
Beginning balance	29
Restructuring charges recognized	2	91
Non-cash charges	0
Cash payments	(20)
Other	(4)
Ending balance	7	29
Strategic Growth Initiative Plan | Corporate
Cost Alignment Plan
Beginning balance	37
Restructuring charges recognized	87	94
Non-cash charges	(10)
Cash payments	(61)
Other	(14)
Ending balance	39	37
Other Accrued Liabilities | Strategic Growth Initiative Plan
Cost Alignment Plan
Beginning balance	117
Ending balance	99	117
Other Noncurrent Liabilities | Strategic Growth Initiative Plan
Cost Alignment Plan
Beginning balance	33
Ending balance	$ 11	$ 33