XML 66 R54.htm IDEA: XBRL DOCUMENT v3.24.3

Hedging Activities - Summary of Derivative Instruments Gain (Loss) (Details) - USD ($)	3 Months Ended		6 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Derivatives, Fair Value [Line Items]
Derivatives designated as cash flow and other hedges:	$ 0	$ 0	$ 0	$ 0
Derivatives designated for hedge accounting | Cross-currency swaps | Net Investment Hedging
Derivatives, Fair Value [Line Items]
Derivatives designated as net investment hedges:	(20,000,000)	27,000,000	(13,000,000)	7,000,000
Derivatives designated for hedge accounting | Cross-currency swaps | Cash Flow Hedges
Derivatives, Fair Value [Line Items]
Derivatives designated as cash flow and other hedges:	(14,000,000)	33,000,000	(14,000,000)	27,000,000
Derivatives designated for hedge accounting | Foreign currency forwards | Cash Flow Hedges
Derivatives, Fair Value [Line Items]
Derivatives designated as cash flow and other hedges:	2,000,000	0	2,000,000	0
Derivatives designated for hedge accounting | Fixed interest rate swaps | Cash Flow Hedges
Derivatives, Fair Value [Line Items]
Derivatives designated as cash flow and other hedges:	$ 0	$ 0	$ 0	$ 16,000,000

X

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

X

- Definition

Amount, before tax, of reclassification of gain (loss) from accumulated other comprehensive income (AOCI) for derivative instrument designated and qualifying as cash flow hedge included in assessment of hedge effectiveness.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 220
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 11
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482790/220-10-45-11

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 220
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 15
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482790/220-10-45-15

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Name Accounting Standards Codification
-Section 50
-Paragraph 4C
-Subparagraph (c)
-SubTopic 10
-Topic 815
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480434/815-10-50-4C

+ Details

Name:	us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationBeforeTax
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

X

- Definition

Amount, before tax, of reclassification from accumulated other comprehensive income (AOCI) for gain (loss) from derivative designated and qualifying as net investment hedge.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 4CCC
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480434/815-10-50-4CCC

+ Details

Name:	us-gaap_OtherComprehensiveIncomeLossNetInvestmentHedgeGainLossReclassificationBeforeTax
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

X

- Details

Name:	us-gaap_HedgingDesignationAxis=us-gaap_DesignatedAsHedgingInstrumentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

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

X

- Details

Name:	us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis=us-gaap_NetInvestmentHedgingMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis=us-gaap_CashFlowHedgingMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

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

X

- Details

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