Goodwill and Intangible Assets, Net - Schedule of Changes in the Carrying Amount of Goodwill and Narrative (Details) $ in Millions	6 Months Ended
	Sep. 30, 2019 USD ($)
Goodwill [Roll Forward]
Beginning balance	$ 9,358
Goodwill acquired	54
Acquisition accounting, transfers and other adjustments	11
Foreign currency translation adjustments, net	(15)
Ending balance	9,408
U.S. Pharmaceutical and Specialty Solutions
Goodwill [Roll Forward]
Beginning balance	4,078
Goodwill acquired	0
Acquisition accounting, transfers and other adjustments	0
Foreign currency translation adjustments, net	(18)
Ending balance	4,060
European Pharmaceutical Solutions
Goodwill [Roll Forward]
Beginning balance	0
Goodwill acquired	54
Acquisition accounting, transfers and other adjustments	4
Foreign currency translation adjustments, net	(1)
Ending balance	57
Medical-Surgical Solutions
Goodwill [Roll Forward]
Beginning balance	2,451
Goodwill acquired	0
Acquisition accounting, transfers and other adjustments	7
Foreign currency translation adjustments, net	0
Ending balance	2,458
Other
Goodwill [Roll Forward]
Beginning balance	2,829
Goodwill acquired	0
Acquisition accounting, transfers and other adjustments	0
Foreign currency translation adjustments, net	4
Ending balance	$ 2,833