Segments of Business - Segment Assets and Long-lived Assets by Geographical Areas (Details) - USD ($) $ in Millions	Mar. 31, 2022	Mar. 31, 2021
Segment assets
Total assets	$ 63,298	$ 65,015
Long-lived assets
Total long-lived assets	2,412	3,094
United States
Long-lived assets
Total long-lived assets	2,060	2,110
Foreign
Long-lived assets
Total long-lived assets	352	984
Operating Segments | U.S. Pharmaceutical
Segment assets
Total assets	38,346	35,236
Operating Segments | International
Segment assets
Total assets	13,717	14,987
Operating Segments | Medical-Surgical Solutions
Segment assets
Total assets	5,830	5,986
Operating Segments | Prescription Technology Solutions
Segment assets
Total assets	3,528	3,446
Corporate
Segment assets
Total assets	$ 1,877	$ 5,360