Goodwill and Intangible Assets, Net - Schedule of Changes in the Carrying Amount of Goodwill and Narrative (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2019	Dec. 31, 2018
Goodwill [Roll Forward]
Beginning balance			$ 9,358
Goodwill acquired			56
Acquisition accounting, transfers and other adjustments			12
Other changes/disposals			(6)
Impairment charges	$ (2)	$ (21)	(2)	$ (591)
Foreign currency translation adjustments, net			38
Ending balance	9,456		9,456
U.S. Pharmaceutical and Specialty Solutions
Goodwill [Roll Forward]
Beginning balance			4,078
Goodwill acquired			0
Acquisition accounting, transfers and other adjustments			1
Other changes/disposals			(1)
Impairment charges			0
Foreign currency translation adjustments, net			0
Ending balance	4,078		4,078
European Pharmaceutical Solutions
Goodwill [Roll Forward]
Beginning balance			0
Goodwill acquired			56
Acquisition accounting, transfers and other adjustments			4
Other changes/disposals			0
Impairment charges			0	$ (570)
Foreign currency translation adjustments, net			3
Ending balance	63		63
Medical-Surgical Solutions
Goodwill [Roll Forward]
Beginning balance			2,451
Goodwill acquired			0
Acquisition accounting, transfers and other adjustments			7
Other changes/disposals			(5)
Impairment charges			0
Foreign currency translation adjustments, net			0
Ending balance	2,453		2,453
Other
Goodwill [Roll Forward]
Beginning balance			2,829
Goodwill acquired			0
Acquisition accounting, transfers and other adjustments			0
Other changes/disposals			0
Impairment charges			(2)
Foreign currency translation adjustments, net			35
Ending balance	$ 2,862		$ 2,862