Restructuring, Impairment and Related Charges - Summary of Restructuring Charges (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2019	Dec. 31, 2018
Restructuring Cost and Reserve [Line Items]
Net restructuring charges recognized	$ 136	$ 110	$ 204	$ 288
Fiscal 2019 Initiatives
Restructuring Cost and Reserve [Line Items]
Severance and employee-related costs, net	12	42	33	66
Exit-related costs	20	26	53	124
Asset impairments and accelerated depreciation and amortization	5	3	17	25
Net restructuring charges recognized	37	71	103	215
Operating Segments | U.S. Pharmaceutical and Specialty Solutions | Fiscal 2019 Initiatives
Restructuring Cost and Reserve [Line Items]
Severance and employee-related costs, net	3	1	4	4
Exit-related costs	0	1	0	7
Asset impairments and accelerated depreciation and amortization	0	2	0	6
Net restructuring charges recognized	3	4	4	17
Operating Segments | European Pharmaceutical Solutions | Fiscal 2019 Initiatives
Restructuring Cost and Reserve [Line Items]
Severance and employee-related costs, net	1	0	3	0
Exit-related costs	2	4	7	4
Asset impairments and accelerated depreciation and amortization	2	0	8	0
Net restructuring charges recognized	5	4	18	4
Operating Segments | Medical-Surgical Solutions | Fiscal 2019 Initiatives
Restructuring Cost and Reserve [Line Items]
Severance and employee-related costs, net	1	0	2	10
Exit-related costs	5	5	9	12
Asset impairments and accelerated depreciation and amortization	0	1	1	2
Net restructuring charges recognized	6	6	12	24
Operating Segments | Other | Fiscal 2019 Initiatives
Restructuring Cost and Reserve [Line Items]
Severance and employee-related costs, net	0	9	1	16
Exit-related costs	0	0	1	56
Asset impairments and accelerated depreciation and amortization	0	0	0	17
Net restructuring charges recognized	0	9	2	89
Corporate | Fiscal 2019 Initiatives
Restructuring Cost and Reserve [Line Items]
Severance and employee-related costs, net	7	32	23	36
Exit-related costs	13	16	36	45
Asset impairments and accelerated depreciation and amortization	3	0	8	0
Net restructuring charges recognized	$ 23	$ 48	$ 67	$ 81