Earnings Per Share Attributable to Cardinal Health, Inc. (Reconciliation of Common Shares Used to Compute Basic and Diluted EPS) (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	12 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2019
Earnings Per Share [Abstract]
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	$ 612	$ (3,693)	$ 1,365
Net earnings attributable to noncontrolling interest	(1)	(3)	(2)
Net Income (Loss) Attributable to Parent	$ 611	$ (3,696)	$ 1,363
Weighted-average common shares–basic (in shares)	292	293	300
Effect of dilutive securities:
Employee stock options, restricted share units, and performance share units (in shares)	2	0	1
Weighted-average common shares–diluted (in shares)	294	293	301
Diluted earnings per common share attributable to Cardinal Health, Inc.:
Earnings Per Share, Basic	$ 2.09	$ (12.61)	$ 4.55
Earnings Per Share, Diluted	$ 2.08	$ (12.61)	$ 4.53