Restructuring, Impairment and Related Charges - Summary of Details for Charges Recorded (Details) - USD ($) $ in Millions	12 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Other
Restructuring Cost and Reserve [Line Items]
Total		$ 91
Strategic Growth Initiative Plan
Restructuring Cost and Reserve [Line Items]
Severance and employee-related costs, net	$ 40	154
Exit-related costs	75	144
Asset impairments and accelerated depreciation	16	33
Total	131	331
Strategic Growth Initiative Plan | Operating Segments | U.S. Pharmaceutical and Specialty Solutions
Restructuring Cost and Reserve [Line Items]
Severance and employee-related costs, net	3	50
Exit-related costs	0	7
Asset impairments and accelerated depreciation	0	6
Total	3	63
Strategic Growth Initiative Plan | Operating Segments | European Pharmaceutical Solutions
Restructuring Cost and Reserve [Line Items]
Severance and employee-related costs, net	1	33
Exit-related costs	11	3
Asset impairments and accelerated depreciation	5	5
Total	17	41
Strategic Growth Initiative Plan | Operating Segments | Medical-Surgical Solutions
Restructuring Cost and Reserve [Line Items]
Severance and employee-related costs, net	2	19
Exit-related costs	19	20
Asset impairments and accelerated depreciation	1	3
Total	22	42
Strategic Growth Initiative Plan | Operating Segments | Other
Restructuring Cost and Reserve [Line Items]
Severance and employee-related costs, net	1	16
Exit-related costs	1	57
Asset impairments and accelerated depreciation	0	18
Total	2	91
Strategic Growth Initiative Plan | Corporate
Restructuring Cost and Reserve [Line Items]
Severance and employee-related costs, net	33	36
Exit-related costs	44	57
Asset impairments and accelerated depreciation	10	1
Total	$ 87	$ 94