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	3 Months Ended						12 Months Ended
	Mar. 31, 2024	Dec. 31, 2023	Sep. 30, 2023	Mar. 31, 2023	Dec. 31, 2022	Sep. 30, 2022	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2022
Earnings Per Share [Abstract]
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	$ 262	$ 369	$ (11)	$ 367	$ (77)	$ 99	$ 853	$ 331	$ (937)
Net earnings attributable to noncontrolling interest							(1)	(1)	(1)
Net earnings/(loss)	$ 261	$ 368	$ (12)	$ 365	$ (77)	$ 98	$ 852	$ 330	$ (938)
Weighted-average common shares–basic (in shares)							245	261	279
Effect of dilutive securities:
Employee stock options, restricted share units, and performance share units (in shares)							2		0
Weighted-average common shares–diluted (in shares)							247	262	279
Diluted earnings per common share attributable to Cardinal Health, Inc.:
Basic (in dollars per share)	$ 1.07	$ 1.50	$ (0.05)	$ 1.43	$ (0.30)	$ 0.36	$ 3.48	$ 1.27	$ (3.37)
Diluted (in dollars per share)	$ 1.07	$ 1.50	$ (0.05)	$ 1.41	$ (0.30)	$ 0.36	$ 3.45	$ 1.26	$ (3.37)