Shareholders' Equity (Changes in the Accumulated Other Comprehensive Income (Loss)) (Details) - USD ($) $ in Millions	12 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2016
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at beginning of period	$ 6,828	$ 6,571	$ 6,256
Amounts reclassified to earnings	(23)	0	0
Total other comprehensive income/(loss), net of tax	33	(9)	(93)
Total comprehensive income/(loss) attributable to Cardinal Health, Inc., net of tax of $1 million	33	(9)	(93)
Balance at end of period	6,059	6,828	6,571
Other comprehensive loss, tax	(1)	(9)
Foreign Currency Translation Adjustments and other
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at beginning of period	(148)	(123)
Other comprehensive income/(loss), net before reclassifications	58	(25)
Amounts reclassified to earnings	(23)	0
Total other comprehensive income/(loss), net of tax		(25)
Total comprehensive income/(loss) attributable to Cardinal Health, Inc., net of tax of $1 million	35
Balance at end of period	(113)	(148)	(123)
Unrealized Gain/(Loss) on Derivatives, net of tax
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at beginning of period	23	7
Other comprehensive income/(loss), net before reclassifications	0	19
Amounts reclassified to earnings	(2)	(3)
Total other comprehensive income/(loss), net of tax		16
Total comprehensive income/(loss) attributable to Cardinal Health, Inc., net of tax of $1 million	(2)
Balance at end of period	21	23	7
Accumulated Other Comprehensive Income/(Loss)
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at beginning of period	(125)	(116)	(23)
Other comprehensive income/(loss), net before reclassifications	58	(6)
Amounts reclassified to earnings	(25)	(3)
Total other comprehensive income/(loss), net of tax		(9)
Total comprehensive income/(loss) attributable to Cardinal Health, Inc., net of tax of $1 million	33	(9)	(93)
Balance at end of period	$ (92)	$ (125)	$ (116)