XML 69 R58.htm IDEA: XBRL DOCUMENT
v3.25.3

Hedging Activities - Narrative (Details) € in Millions, $ in Millions | 3 Months Ended | 6 Months Ended |  |  |
--- | --- | --- | --- | --- | ---
Sep. 30, 2025 USD ($) | Jun. 30, 2025 USD ($) | Sep. 30, 2024 USD ($) | Sep. 30, 2025 USD ($) | Sep. 30, 2024 USD ($) | Nov. 05, 2025 EUR (€) | Sep. 30, 2025 CAD ($) | Sep. 30, 2025 EUR (€) | Sep. 30, 2025 USD ($) | Mar. 31, 2025 CAD ($) | Mar. 31, 2025 EUR (€) | Mar. 31, 2025 USD ($)
Derivative [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Gains or losses reclassified from accumulated other comprehensive loss | $ 0 |  | $ 0 | $ 0 | $ 0 |  |  |  |  |  |  |
Currency swap | Cash Flow Hedges | Derivatives designated for hedge accounting |  |  |  |  |  |  |  |  |  |  |  |
Derivative [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Gains or losses reclassified from accumulated other comprehensive loss | $ (7,000,000) |  |  |  |  |  |  |  |  |  |  |
Floating interest rate swaps | Cash Flow Hedges | Derivatives designated for hedge accounting |  |  |  |  |  |  |  |  |  |  |  |
Derivative [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Notional amounts of derivative |  | $ 1,400,000,000 |  |  |  |  |  |  |  |  |  |
Notional amount, entered into during period |  | $ 550,000,000 |  |  |  |  |  |  |  |  |  |
CAD | Currency swap | Net Investment Hedging | Derivatives designated for hedge accounting |  |  |  |  |  |  |  |  |  |  |  |
Derivative [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Notional amounts of derivative |  |  |  |  |  |  | $ 6,500 |  |  | $ 6,500 |  |
EUR | Currency swap | Fair Value Hedges | Derivatives designated for hedge accounting |  |  |  |  |  |  |  |  |  |  |  |
Derivative [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Notional amounts of derivative | € |  |  |  |  |  |  |  | € 1,100 |  |  | € 1,100 |
Settled at fair value, net | € |  |  |  |  |  |  |  | € 600 |  |  |  |
EUR | Currency swap | Fair Value Hedges | Derivatives designated for hedge accounting | Subsequent Event |  |  |  |  |  |  |  |  |  |  |  |
Derivative [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Acquired at fair value, net | € |  |  |  |  |  | € 600 |  |  |  |  |  |
USD | Floating interest rate swaps | Fair Value Hedges | Derivatives designated for hedge accounting |  |  |  |  |  |  |  |  |  |  |  |
Derivative [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Notional amounts of derivative |  |  |  |  |  |  |  |  | $ 750,000,000 |  |  | $ 750,000,000
USD | Floating interest rate swaps | Cash Flow Hedges | Derivatives designated for hedge accounting |  |  |  |  |  |  |  |  |  |  |  |
Derivative [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Notional amounts of derivative |  |  |  |  |  |  |  |  | $ 0 |  |  | $ 850,000,000

X
- Definition Derivative Instruments In Hedges, Acquired At Fair Value, Net + References No definition available. + Details
Name: | mck_DerivativeInstrumentsInHedgesAcquiredAtFairValueNet
Namespace Prefix: | mck_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Derivative Instruments In Hedges, Settled At Fair Value, Net + References No definition available. + Details
Name: | mck_DerivativeInstrumentsInHedgesSettledAtFairValueNet
Namespace Prefix: | mck_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Derivative, Notional Amount, Entered Into During Period + References No definition available. + Details
Name: | mck_DerivativeNotionalAmountEnteredIntoDuringPeriod
Namespace Prefix: | mck_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

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 Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 815 -SubTopic 20 -Name Accounting Standards Codification -Section 25 -Paragraph 6A -Publisher FASB -URI https://asc.fasb.org/1943274/2147480682/815-20-25-6A Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 815 -SubTopic 40 -Name Accounting Standards Codification -Section 50 -Paragraph 5 -Subparagraph (f) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480237/815-40-50-5 + Details
Name: | us-gaap_DerivativeLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Nominal or face amount used to calculate payment on derivative. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Topic 815 -SubTopic 10 -Name Accounting Standards Codification -Section 55 -Paragraph 181 -Publisher FASB -URI https://asc.fasb.org/1943274/2147480401/815-10-55-181 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 815 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 1B -Publisher FASB -URI https://asc.fasb.org/1943274/2147480434/815-10-50-1B Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 815 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 1A -Subparagraph (d) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480434/815-10-50-1A + Details
Name: | us-gaap_DerivativeNotionalAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | na
Period Type: | instant

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/exampleRef -Topic 815 -SubTopic 10 -Name Accounting Standards Codification -Section 55 -Paragraph 182 -Publisher FASB -URI https://asc.fasb.org/1943274/2147480401/815-10-55-182 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 815 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 4C -Subparagraph (c) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480434/815-10-50-4C Reference 3: 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 4: 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 + Details
Name: | us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationBeforeTax
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

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

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

X
- Details
Name: | srt_CurrencyAxis=currency_CAD
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: | srt_CurrencyAxis=currency_EUR
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis=us-gaap_FairValueHedgingMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_SubsequentEventTypeAxis=us-gaap_SubsequentEventMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_CurrencyAxis=currency_USD
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |