Segment Information (Revenue by Reportable Segment) (Details) - USD ($) $ in Millions	12 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2019
Segment Reporting Information [Line Items]
Revenue	$ 162,467	$ 152,922	$ 145,534
Non-US [Member]
Segment Reporting Information [Line Items]
Revenue	4,727	4,232	4,071
United States
Segment Reporting Information [Line Items]
Revenue	157,756	148,707	141,479
Operating Segments
Segment Reporting Information [Line Items]
Revenue	162,483	152,939	145,550
Operating Segments | Pharmaceutical
Segment Reporting Information [Line Items]
Revenue	145,796	137,495	129,917
Operating Segments | Pharmaceutical | Pharmaceutical Distribution and Specialty [Member]
Segment Reporting Information [Line Items]
Revenue	144,988	136,693	129,067
Operating Segments | Pharmaceutical | Nuclear Precision Health Services [Member]
Segment Reporting Information [Line Items]
Revenue	808	802	850
Operating Segments | Medical
Segment Reporting Information [Line Items]
Revenue	16,687	15,444	15,633
Operating Segments | Medical | Medical distribution and products [Member]
Segment Reporting Information [Line Items]
Revenue	14,485	13,429	13,833
Operating Segments | Medical | Cardinal Health At Home Solutions [Member]
Segment Reporting Information [Line Items]
Revenue	2,202	2,015	1,800
Corporate
Segment Reporting Information [Line Items]
Revenue	$ (16)	$ (17)	$ (16)