Commitments and Contingent Liabilities - II. Other Litigation and Claims (Narrative) (Details)	Jul. 31, 2020 state	Mar. 02, 2020 state city	Apr. 25, 2018 state city
United States ex rel. Omni Healthcare Inc. v. McKesson Corporation, et al.
Loss Contingencies [Line Items]
Number of cities filed on behalf of | city		33	33
Number of states filed on behalf of		33	33
United States ex rel. Hart v. McKesson Corporation, et al., 15-cv-00903-RA
Loss Contingencies [Line Items]
Number of states filed on behalf of	27