Restructuring and Employee Severance Narrative (Details) - USD ($) $ in Millions	12 Months Ended
Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2016
Restructuring Cost and Reserve [Line Items]
Facility Exit and Other Costs	$ 142	$ 5	$ 10
Distributor Contract [Member]
Restructuring Cost and Reserve [Line Items]
Facility Exit and Other Costs	$ 125

Facility exit and other costs primarily consist of lease termination costs, accelerated depreciation, equipment relocation costs, project consulting fees and costs associated with restructuring our delivery of information technology infrastructure services.

No definition available.

Name:	cah_FacilityExitAndOtherCosts
Namespace Prefix:	cah_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration