Goodwill and Intangible Assets, Net - Schedule of Changes in the Carrying Amount of Goodwill (Details) - USD ($) $ in Millions	12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Mar. 31, 2019
Goodwill [Roll Forward]
Goodwill, beginning balance	$ 9,360	$ 9,358
Goodwill acquired	5	76
Acquisition accounting, transfers and other adjustments	2	12
Other changes/disposals	(1)	(6)
Goodwill impairment	(69)	(2)	$ (1,797)
Foreign currency translation adjustments, net	196	(78)
Goodwill, ending balance	9,493	9,360	9,358
U.S. Pharmaceutical
Goodwill [Roll Forward]
Goodwill, beginning balance	3,924	3,935
Goodwill acquired	0	0
Acquisition accounting, transfers and other adjustments	0	1
Other changes/disposals	(1)	(1)
Goodwill impairment	0	0
Foreign currency translation adjustments, net	40	(11)
Goodwill, ending balance	3,963	3,924	3,935
International
Goodwill [Roll Forward]
Goodwill, beginning balance	1,443	1,446
Goodwill acquired	5	62
Acquisition accounting, transfers and other adjustments	0	4
Other changes/disposals	0	0
Goodwill impairment	(69)	(2)	(1,776)
Foreign currency translation adjustments, net	156	(67)
Goodwill, ending balance	1,535	1,443	1,446
Medical-Surgical Solutions
Goodwill [Roll Forward]
Goodwill, beginning balance	2,453	2,451
Goodwill acquired	0	0
Acquisition accounting, transfers and other adjustments	0	7
Other changes/disposals	0	(5)
Goodwill impairment	0	0
Foreign currency translation adjustments, net	0	0
Goodwill, ending balance	2,453	2,453	2,451
Prescription Technology Solutions
Goodwill [Roll Forward]
Goodwill, beginning balance	1,540	1,526
Goodwill acquired	0	14
Acquisition accounting, transfers and other adjustments	2	0
Other changes/disposals	0	0
Goodwill impairment	0	0
Foreign currency translation adjustments, net	0	0
Goodwill, ending balance	$ 1,542	$ 1,540	$ 1,526