Restructuring, Impairment and Related Charges - Summary of Restructuring Charges (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2020	Dec. 31, 2019
Restructuring Cost and Reserve [Line Items]
Severance and employee-related costs, net	$ 9	$ 16	$ 63	$ 39
Exit and other-related costs	15	21	43	54
Asset impairments and accelerated depreciation	16	5	50	17
Total	40	42	156	110
International
Restructuring Cost and Reserve [Line Items]
Total	131		189
Operating Segments | U.S. Pharmaceutical
Restructuring Cost and Reserve [Line Items]
Severance and employee-related costs, net	3	7	10	9
Exit and other-related costs	3	0	8	0
Asset impairments and accelerated depreciation	0	0	0	0
Total	6	7	18	9
Operating Segments | International
Restructuring Cost and Reserve [Line Items]
Severance and employee-related costs, net	2	1	22	5
Exit and other-related costs	5	3	12	9
Asset impairments and accelerated depreciation	9	2	40	8
Total	16	6	74	22
Operating Segments | Medical-Surgical Solutions
Restructuring Cost and Reserve [Line Items]
Severance and employee-related costs, net	(3)	1	0	2
Exit and other-related costs	1	5	3	9
Asset impairments and accelerated depreciation	0	0	1	1
Total	(2)	6	4	12
Operating Segments | Prescription Technology Solutions
Restructuring Cost and Reserve [Line Items]
Severance and employee-related costs, net	0	0	0	0
Exit and other-related costs	0	0	0	0
Asset impairments and accelerated depreciation	0	0	0	0
Total	0	0	0	0
Corporate
Restructuring Cost and Reserve [Line Items]
Severance and employee-related costs, net	7	7	31	23
Exit and other-related costs	6	13	20	36
Asset impairments and accelerated depreciation	7	3	9	8
Total	$ 20	$ 23	$ 60	$ 67