Segment Information Disaggregated Revenue Within Reportable Segments (Details) - USD ($) $ in Millions	3 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue	$ 35,213	$ 32,641
Operating Segments
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue	39,018	32,644
Operating Segments | Pharmaceutical
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue	31,416	28,920
Operating Segments | Pharmaceutical | Nuclear Precision Health Services [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue	207
Operating Segments | Pharmaceutical | Pharmaceutical distribution and specialty [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue	31,209
Operating Segments | Medical
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue	3,801	3,724
Operating Segments | Medical | Cardinal Health At Home [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue	421
Operating Segments | Medical | Medical distribution and products [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue	3,380
Corporate
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue	$ (4)	$ (3)