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Goodwill and Intangible Assets, Net - Schedule of Changes in the Carrying Amount of Goodwill (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Goodwill [Roll Forward]
Beginning balance			$ 9,360
Goodwill acquired			1
Acquisition accounting, transfers and other adjustments			2
Goodwill impairment charges	$ (69)	$ 0	(69)	$ 0
Foreign currency translation adjustments, net			120
Ending balance	9,414		9,414
U.S. Pharmaceutical
Goodwill [Roll Forward]
Beginning balance			3,924
Goodwill acquired			0
Acquisition accounting, transfers and other adjustments			0
Goodwill impairment charges			0
Foreign currency translation adjustments, net			39
Ending balance	3,963		3,963
International
Goodwill [Roll Forward]
Beginning balance			1,443
Goodwill acquired			1
Acquisition accounting, transfers and other adjustments			0
Goodwill impairment charges	(69)		(69)
Foreign currency translation adjustments, net			81
Ending balance	1,456		1,456
Medical-Surgical Solutions
Goodwill [Roll Forward]
Beginning balance			2,453
Goodwill acquired			0
Acquisition accounting, transfers and other adjustments			0
Goodwill impairment charges			0
Foreign currency translation adjustments, net			0
Ending balance	2,453		2,453
Prescription Technology Solutions
Goodwill [Roll Forward]
Beginning balance			1,540
Goodwill acquired			0
Acquisition accounting, transfers and other adjustments			2
Goodwill impairment charges			0
Foreign currency translation adjustments, net			0
Ending balance	$ 1,542		$ 1,542