Basis of Presentation and Summary of Significant Accounting Policies (Revision of Consolidated Statement of Comprehensive Income (Loss)) (Details) - USD ($) $ 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
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net earnings/(loss)	$ 262	$ 369	$ (11)	$ 367	$ (77)	$ 99	$ 853	$ 331	$ (937)
Total comprehensive income/(loss), net of tax	257	379	(25)	371	(47)	37	837	294	(1,017)
Total comprehensive income/(loss) attributable to Cardinal Health, Inc.	256	378	(26)	369	(47)	36	$ 836	293	(1,018)
As Reported
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net earnings/(loss)	259	354	6	347	(130)	111		262	(932)
Total comprehensive income/(loss), net of tax	254	364	(8)	351	(100)	49		225	(1,012)
Total comprehensive income/(loss) attributable to Cardinal Health, Inc.	253	363	(9)	349	(100)	48		224	(1,013)
Adjustment
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net earnings/(loss)	3	15	(17)	20	53	(12)		69	(5)
Total comprehensive income/(loss), net of tax	3	15	(17)	20	53	(12)		69	(5)
Total comprehensive income/(loss) attributable to Cardinal Health, Inc.	$ 3	$ 15	$ (17)	$ 20	$ 53	$ (12)		$ 69	$ (5)