Adjustment to the fair value of the debt instrument resulting from the termination of interest rate swap.

No definition available.

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

- Definition

The end date of the period reflected on the cover page if a periodic report. For all other reports and registration statements containing historical data, it is the date up through which that historical data is presented. If there is no historical data in the report, use the filing date. The format of the date is CCYY-MM-DD.

+ References

No definition available.

+ Details

Name:	dei_DocumentPeriodEndDate
Namespace Prefix:	dei_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of increase (decrease) in the fair value of derivatives recognized in the income statement.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4A
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=84234895&loc=SL5618551-113959

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4C
-Subparagraph (a),(c),(d),(e)
-URI http://asc.fasb.org/extlink&oid=84234895&loc=SL5624171-113959

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_DerivativeLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=us-gaap_InterestRateSwapMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_IncomeStatementLocationAxis=us-gaap_InterestExpenseMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=cah_FixedRateDebtMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Financial Instruments (Schedule of Gain/(Loss) Recognized in Earnings for Interest Rate Contracts Designated as Fair Value Hedges) (Details) - USD ($) $ in Millions	1 Months Ended	12 Months Ended
	Dec. 31, 2014	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2015
Derivative [Line Items]
Document Period End Date		Jun. 30, 2017
Fair value adjustment related to previously terminated swaps	$ 22		$ 22
Fair Value Hedging \| Interest Rate Swaps \| Interest Expense, Net
Derivative [Line Items]
Gain/(loss) on derivative		$ 17	23	$ 14
Fair Value Hedging \| Fixed-Rate Debt \| Interest Expense, Net
Derivative [Line Items]
Gain/(loss) on derivative		$ (17)	$ (23)	$ (14)