Segment Information (Revenue by Reportable Segment) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2019	Dec. 31, 2018
Segment Reporting Information [Line Items]
Total revenue	$ 39,735	$ 37,740	$ 77,076	$ 72,953
Operating Segments
Segment Reporting Information [Line Items]
Total revenue	39,737	37,746	77,082	72,962
Operating Segments | Pharmaceutical
Segment Reporting Information [Line Items]
Total revenue	35,714	33,740	69,142	65,155
Operating Segments | Medical
Segment Reporting Information [Line Items]
Total revenue	4,023	4,006	7,940	7,807
Corporate
Segment Reporting Information [Line Items]
Total revenue	(2)	(6)	(6)	(9)
Pharmaceutical Distribution and Specialty [Member] | Operating Segments | Pharmaceutical
Segment Reporting Information [Line Items]
Total revenue	35,501	33,534	68,713	64,742
Nuclear Precision Health Services [Member] | Operating Segments | Pharmaceutical
Segment Reporting Information [Line Items]
Total revenue	213	206	429	413
Medical distribution and products [Member] | Operating Segments | Medical
Segment Reporting Information [Line Items]
Total revenue	3,498	3,527	6,944	6,907
Cardinal Health At Home [Member] | Operating Segments | Medical
Segment Reporting Information [Line Items]
Total revenue	$ 525	$ 479	$ 996	$ 900