XML 138 R120.htm IDEA: XBRL DOCUMENT
v3.25.1

Stockholders' Equity (Deficit) - Schedule of Changes in Accumulated Other Comprehensive Income by Component (Details) - USD ($) | 12 Months Ended
--- | ---
Mar. 31, 2025 | Mar. 31, 2024 | Mar. 31, 2023
Accumulated Other Comprehensive Income (Loss), Change, Net of Tax [Roll Forward] |  |  |
Beginning balance | $ (1,599,000,000) | $ (1,490,000,000) | $ (1,792,000,000)
Other comprehensive income (loss), net of tax | (51,000,000) | 24,000,000 | 673,000,000
Other comprehensive income (loss) attributable to McKesson | (51,000,000) | 24,000,000 | 673,000,000
Ending balance | (1,694,000,000) | (1,599,000,000) | (1,490,000,000)
Other comprehensive income (loss), cash flow hedge, gain (loss), reclassification before tax | 0 | 0 | 0
Reclassification to income statement, tax expense | 11,000,000 |  | 6,000,000
Disposed of by Sale | Canadian Retail Disposal Group |  |  |
Accumulated Other Comprehensive Income (Loss), Change, Net of Tax [Roll Forward] |  |  |
Accumulated other comprehensive loss in charge for remeasurement to fair value | 48,000,000 |  |
Net Investment Hedging | Derivatives designated for hedge accounting: | Cross-currency swaps |  |  |
Accumulated Other Comprehensive Income (Loss), Change, Net of Tax [Roll Forward] |  |  |
Other comprehensive income (loss), net investment hedge, gain (loss) | 80,000,000 | 3,000,000 | 28,000,000
Net Investment Hedging | Derivatives designated for hedge accounting: | Euro Denominated Notes |  |  |
Accumulated Other Comprehensive Income (Loss), Change, Net of Tax [Roll Forward] |  |  |
Other comprehensive income (loss), net investment hedge, gain (loss) | 0 | 0 | 7,000,000
Cash Flow Hedging | Derivatives designated for hedge accounting: | Fixed interest rate swaps |  |  |
Accumulated Other Comprehensive Income (Loss), Change, Net of Tax [Roll Forward] |  |  |
Other comprehensive income (loss), cash flow hedge, gain (loss), reclassification before tax | 0 | 14,000,000 | (30,000,000)
Cash Flow Hedging | Derivatives designated for hedge accounting: | Cross-currency swaps |  |  |
Accumulated Other Comprehensive Income (Loss), Change, Net of Tax [Roll Forward] |  |  |
Other comprehensive income (loss), cash flow hedge, gain (loss), reclassification before tax | (4,000,000) | 39,000,000 | (54,000,000)
Total Accumulated Other Comprehensive Loss |  |  |
Accumulated Other Comprehensive Income (Loss), Change, Net of Tax [Roll Forward] |  |  |
Beginning balance | (881,000,000) | (905,000,000) | (1,534,000,000)
Other comprehensive income (loss) before reclassifications | (176,000,000) | 26,000,000 | (179,000,000)
Amount reclassified to earnings and other | 125,000,000 | (2,000,000) | 852,000,000
Other comprehensive income (loss), net of tax | (51,000,000) | 24,000,000 | 673,000,000
Less: amounts attributable to noncontrolling interests |  |  | 44,000,000
Other comprehensive income (loss) attributable to McKesson |  |  | 629,000,000
Ending balance | (932,000,000) | (881,000,000) | (905,000,000)
Foreign Currency Translation Adjustments, Net of Tax |  |  |
Accumulated Other Comprehensive Income (Loss), Change, Net of Tax [Roll Forward] |  |  |
Beginning balance | (856,000,000) | (847,000,000) | (1,504,000,000)
Other comprehensive income (loss) before reclassifications | (214,000,000) | (9,000,000) | (329,000,000)
Amount reclassified to earnings and other | 81,000,000 | 0 | 1,027,000,000
Other comprehensive income (loss), net of tax | (133,000,000) | (9,000,000) | 698,000,000
Ending balance | (989,000,000) | (856,000,000) | (847,000,000)
Foreign Currency Translation Adjustments, Net of Tax |  |  |
Accumulated Other Comprehensive Income (Loss), Change, Net of Tax [Roll Forward] |  |  |
Other comprehensive income (loss) attributable to McKesson |  |  | 657,000,000
Foreign Currency Translation Adjustments, Net of Tax |  |  |
Accumulated Other Comprehensive Income (Loss), Change, Net of Tax [Roll Forward] |  |  |
Less: amounts attributable to noncontrolling interests |  |  | 41,000,000
Unrealized Gains (Losses) on Net Investment Hedges, Net of Tax |  |  |
Accumulated Other Comprehensive Income (Loss), Change, Net of Tax [Roll Forward] |  |  |
Beginning balance | (12,000,000) | (14,000,000) | 10,000,000
Other comprehensive income (loss) before reclassifications | 59,000,000 | 2,000,000 | 112,000,000
Amount reclassified to earnings and other | 0 | 0 | (136,000,000)
Other comprehensive income (loss), net of tax | 59,000,000 | 2,000,000 | (24,000,000)
Ending balance | 47,000,000 | (12,000,000) | (14,000,000)
Unrealized Gains (Losses) on Net Investment Hedges, Net of Tax | Net Investment Hedging |  |  |
Accumulated Other Comprehensive Income (Loss), Change, Net of Tax [Roll Forward] |  |  |
Other comprehensive income (loss) before reclassification, tax | (21,000,000) | (1,000,000) | (33,000,000)
Unrealized Gains (Losses) on Net Investment Hedges, Net of Tax | Cash Flow Hedging |  |  |
Accumulated Other Comprehensive Income (Loss), Change, Net of Tax [Roll Forward] |  |  |
Other comprehensive income (loss) before reclassification, tax | (3,000,000) | 14,000,000 | (21,000,000)
Unrealized Gains (Losses) on Net Investment Hedges, Net of Tax |  |  |
Accumulated Other Comprehensive Income (Loss), Change, Net of Tax [Roll Forward] |  |  |
Less: amounts attributable to noncontrolling interests |  |  | 0
Unrealized Gains (Losses) on Net Investment Hedges, Net of Tax |  |  |
Accumulated Other Comprehensive Income (Loss), Change, Net of Tax [Roll Forward] |  |  |
Other comprehensive income (loss) attributable to McKesson |  |  | (24,000,000)
Unrealized Gains (Losses) on Cash Flow and other Hedges, Net of Tax |  |  |
Accumulated Other Comprehensive Income (Loss), Change, Net of Tax [Roll Forward] |  |  |
Beginning balance | 3,000,000 | (36,000,000) | 27,000,000
Other comprehensive income (loss) before reclassifications | (5,000,000) | 39,000,000 | 10,000,000
Amount reclassified to earnings and other | (2,000,000) | 0 | (73,000,000)
Other comprehensive income (loss), net of tax | (7,000,000) | 39,000,000 | (63,000,000)
Ending balance | (4,000,000) | 3,000,000 | (36,000,000)
Unrealized Gains (Losses) on Cash Flow and other Hedges, Net of Tax |  |  |
Accumulated Other Comprehensive Income (Loss), Change, Net of Tax [Roll Forward] |  |  |
Less: amounts attributable to noncontrolling interests |  |  | 0
Unrealized Gains (Losses) on Cash Flow and other Hedges, Net of Tax |  |  |
Accumulated Other Comprehensive Income (Loss), Change, Net of Tax [Roll Forward] |  |  |
Other comprehensive income (loss) attributable to McKesson |  |  | (63,000,000)
Unrealized Gains (Losses) and Other Components of Benefit Plans, Net of Tax |  |  |
Accumulated Other Comprehensive Income (Loss), Change, Net of Tax [Roll Forward] |  |  |
Beginning balance | (16,000,000) | (8,000,000) | (67,000,000)
Other comprehensive income (loss) before reclassifications | (16,000,000) | (6,000,000) | 28,000,000
Amount reclassified to earnings and other | 46,000,000 | (2,000,000) | 34,000,000
Other comprehensive income (loss), net of tax | 30,000,000 | (8,000,000) | 62,000,000
Ending balance | $ 14,000,000 | $ (16,000,000) | (8,000,000)
Unrealized Gains (Losses) and Other Components of Benefit Plans, Net of Tax |  |  |
Accumulated Other Comprehensive Income (Loss), Change, Net of Tax [Roll Forward] |  |  |
Less: amounts attributable to noncontrolling interests |  |  | 3,000,000
Unrealized Gains (Losses) and Other Components of Benefit Plans, Net of Tax |  |  |
Accumulated Other Comprehensive Income (Loss), Change, Net of Tax [Roll Forward] |  |  |
Other comprehensive income (loss) attributable to McKesson |  |  | $ 59,000,000

X
- Definition Disposal Group, Including Discontinued Operation, Accumulated Other Comprehensive Gain (Loss) in Charge for Remeasurement to Fair Value + References No definition available. + Details
Name: | mck_DisposalGroupIncludingDiscontinuedOperationAccumulatedOtherComprehensiveLossInChargeForRemeasurementToFairValue
Namespace Prefix: | mck_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period. + References No definition available. + Details
Name: | us-gaap_AOCIAttributableToParentNetOfTaxRollForward
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount after tax, before reclassification adjustments of other comprehensive income (loss). + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 14A -Publisher FASB -URI https://asc.fasb.org/1943274/2147482790/220-10-45-14A Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 220 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 5 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482765/220-10-50-5 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 830 -SubTopic 30 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org/1943274/2147481674/830-30-50-1 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 830 -SubTopic 30 -Name Accounting Standards Codification -Section 45 -Paragraph 17 -Publisher FASB -URI https://asc.fasb.org/1943274/2147481694/830-30-45-17 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Topic 830 -SubTopic 30 -Name Accounting Standards Codification -Section 45 -Paragraph 20 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481694/830-30-45-20 Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Topic 944 -SubTopic 220 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-04(19)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147477250/944-220-S99-1 Reference 7: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 220 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 4 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482765/220-10-50-4 Reference 8: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Section 55 -Paragraph 15 -SubTopic 10 -Topic 220 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482739/220-10-55-15 + Details
Name: | us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of tax expense (benefit) allocated to other comprehensive income (loss) before reclassification adjustment from accumulated other comprehensive income (loss). + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Section 45 -Paragraph 12 -SubTopic 10 -Topic 220 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482790/220-10-45-12 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 220 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 4 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482765/220-10-50-4 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 944 -SubTopic 220 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-04(19)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147477250/944-220-S99-1 + Details
Name: | us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsTax
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
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
- Definition Amount after tax and reclassification adjustments of other comprehensive income (loss). + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Section 50 -Paragraph 2 -SubTopic 10 -Topic 505 -Publisher FASB -URI https://asc.fasb.org/1943274/2147481112/505-10-50-2 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 250 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 6 -Publisher FASB -URI https://asc.fasb.org/1943274/2147483443/250-10-50-6 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 830 -SubTopic 30 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org/1943274/2147481674/830-30-50-1 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 830 -SubTopic 30 -Name Accounting Standards Codification -Section 45 -Paragraph 17 -Publisher FASB -URI https://asc.fasb.org/1943274/2147481694/830-30-45-17 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Topic 944 -SubTopic 220 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-04(19)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147477250/944-220-S99-1 Reference 6: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 220 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 4 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482765/220-10-50-4 Reference 7: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 220 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 5 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482765/220-10-50-5 Reference 8: http://www.xbrl.org/2003/role/disclosureRef -Topic 830 -SubTopic 30 -Name Accounting Standards Codification -Section 45 -Paragraph 20 -Publisher FASB -URI https://asc.fasb.org/1943274/2147481694/830-30-45-20 Reference 9: http://www.xbrl.org/2003/role/disclosureRef -Topic 220 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03(21)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147483621/220-10-S99-2 Reference 10: http://www.xbrl.org/2003/role/disclosureRef -Topic 942 -SubTopic 220 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-04(23)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147478524/942-220-S99-1 Reference 11: http://www.xbrl.org/2003/role/disclosureRef -Topic 220 -SubTopic 10 -Name Accounting Standards Codification -Section 45 -Paragraph 1B -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482790/220-10-45-1B Reference 12: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Section 55 -Paragraph 15 -SubTopic 10 -Topic 220 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482739/220-10-55-15 Reference 13: http://www.xbrl.org/2003/role/disclosureRef -Topic 220 -SubTopic 10 -Name Accounting Standards Codification -Section 45 -Paragraph 1A -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482790/220-10-45-1A + Details
Name: | us-gaap_OtherComprehensiveIncomeLossNetOfTax
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount after tax of other comprehensive income (loss) attributable to noncontrolling interests. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 810 -SubTopic 10 -Name Accounting Standards Codification -Section 45 -Paragraph 19 -Publisher FASB -URI https://asc.fasb.org/1943274/2147481231/810-10-45-19 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Section 45 -Paragraph 20 -SubTopic 10 -Topic 810 -Publisher FASB -URI https://asc.fasb.org/1943274/2147481231/810-10-45-20 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Section 50 -Paragraph 1A -Subparagraph (c)(3) -SubTopic 10 -Topic 810 -Publisher FASB -URI https://asc.fasb.org/1943274/2147481203/810-10-50-1A Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 250 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 6 -Publisher FASB -URI https://asc.fasb.org/1943274/2147483443/250-10-50-6 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Topic 220 -SubTopic 10 -Name Accounting Standards Codification -Section 45 -Paragraph 1B -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482790/220-10-45-1B Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Topic 220 -SubTopic 10 -Name Accounting Standards Codification -Section 45 -Paragraph 1A -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482790/220-10-45-1A + Details
Name: | us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToNoncontrollingInterest
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount after tax of other comprehensive income (loss) attributable to parent entity. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 810 -SubTopic 10 -Name Accounting Standards Codification -Section 45 -Paragraph 19 -Publisher FASB -URI https://asc.fasb.org/1943274/2147481231/810-10-45-19 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Section 45 -Paragraph 20 -SubTopic 10 -Topic 810 -Publisher FASB -URI https://asc.fasb.org/1943274/2147481231/810-10-45-20 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Section 50 -Paragraph 1A -Subparagraph (c)(3) -SubTopic 10 -Topic 810 -Publisher FASB -URI https://asc.fasb.org/1943274/2147481203/810-10-50-1A Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 250 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 6 -Publisher FASB -URI https://asc.fasb.org/1943274/2147483443/250-10-50-6 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Topic 220 -SubTopic 10 -Name Accounting Standards Codification -Section 45 -Paragraph 1B -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482790/220-10-45-1B Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Topic 220 -SubTopic 10 -Name Accounting Standards Codification -Section 45 -Paragraph 1A -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482790/220-10-45-1A + Details
Name: | us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount after tax of reclassification adjustments of other comprehensive income (loss). + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 14A -Publisher FASB -URI https://asc.fasb.org/1943274/2147482790/220-10-45-14A Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 220 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 5 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482765/220-10-50-5 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 830 -SubTopic 30 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org/1943274/2147481674/830-30-50-1 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 830 -SubTopic 30 -Name Accounting Standards Codification -Section 45 -Paragraph 17 -Publisher FASB -URI https://asc.fasb.org/1943274/2147481694/830-30-45-17 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Topic 830 -SubTopic 30 -Name Accounting Standards Codification -Section 45 -Paragraph 20 -Subparagraph (d) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481694/830-30-45-20 Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Topic 944 -SubTopic 220 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-04(19)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147477250/944-220-S99-1 Reference 7: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 220 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 4 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482765/220-10-50-4 Reference 8: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Section 55 -Paragraph 15 -SubTopic 10 -Topic 220 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482739/220-10-55-15 + Details
Name: | us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of tax expense (benefit) of reclassification adjustment from accumulated other comprehensive income (loss). + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Section 45 -Paragraph 12 -SubTopic 10 -Topic 220 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482790/220-10-45-12 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 220 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 4 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482765/220-10-50-4 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 944 -SubTopic 220 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-04(19)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147477250/944-220-S99-1 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 220 -SubTopic 10 -Name Accounting Standards Codification -Section 45 -Paragraph 17A -Publisher FASB -URI https://asc.fasb.org/1943274/2147482790/220-10-45-17A + Details
Name: | us-gaap_ReclassificationFromAociCurrentPeriodTax
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of equity (deficit) attributable to parent and noncontrolling interest. Excludes temporary equity. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 250 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 6 -Publisher FASB -URI https://asc.fasb.org/1943274/2147483443/250-10-50-6 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 805 -SubTopic 60 -Name Accounting Standards Codification -Section 65 -Paragraph 1 -Subparagraph (g) -Publisher FASB -URI https://asc.fasb.org/1943274/2147476176/805-60-65-1 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 805 -SubTopic 60 -Name Accounting Standards Codification -Section 65 -Paragraph 1 -Subparagraph (d)(1) -Publisher FASB -URI https://asc.fasb.org/1943274/2147476176/805-60-65-1 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 740 -SubTopic 323 -Name Accounting Standards Codification -Section 65 -Paragraph 2 -Subparagraph (e) -Publisher FASB -URI https://asc.fasb.org/1943274/2147478666/740-323-65-2 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Topic 740 -SubTopic 323 -Name Accounting Standards Codification -Section 65 -Paragraph 2 -Subparagraph (g)(4) -Publisher FASB -URI https://asc.fasb.org/1943274/2147478666/740-323-65-2 Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Topic 740 -SubTopic 323 -Name Accounting Standards Codification -Section 65 -Paragraph 2 -Subparagraph (d)(2) -Publisher FASB -URI https://asc.fasb.org/1943274/2147478666/740-323-65-2 Reference 7: http://www.xbrl.org/2003/role/disclosureRef -Topic 740 -SubTopic 323 -Name Accounting Standards Codification -Section 65 -Paragraph 2 -Subparagraph (d)(1) -Publisher FASB -URI https://asc.fasb.org/1943274/2147478666/740-323-65-2 Reference 8: http://www.xbrl.org/2003/role/disclosureRef -Topic 848 -SubTopic 10 -Name Accounting Standards Codification -Section 65 -Paragraph 2 -Subparagraph (a)(3)(iii)(03) -Publisher FASB -URI https://asc.fasb.org/1943274/2147483550/848-10-65-2 Reference 9: http://www.xbrl.org/2003/role/disclosureRef -Topic 842 -SubTopic 10 -Name Accounting Standards Codification -Section 65 -Paragraph 8 -Subparagraph (c)(3) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479832/842-10-65-8 Reference 10: http://www.xbrl.org/2003/role/disclosureRef -Topic 250 -SubTopic 10 -Name Accounting Standards Codification -Section 45 -Paragraph 24 -Publisher FASB -URI https://asc.fasb.org/1943274/2147483421/250-10-45-24 Reference 11: http://www.xbrl.org/2003/role/disclosureRef -Topic 250 -SubTopic 10 -Name Accounting Standards Codification -Section 45 -Paragraph 23 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147483421/250-10-45-23 Reference 12: http://www.xbrl.org/2003/role/disclosureRef -Topic 250 -SubTopic 10 -Name Accounting Standards Codification -Section 45 -Paragraph 5 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147483421/250-10-45-5 Reference 13: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 10 -Name Accounting Standards Codification -Section 65 -Paragraph 5 -Subparagraph (c)(2) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479654/326-10-65-5 Reference 14: http://www.xbrl.org/2003/role/disclosureRef -Topic 815 -SubTopic 20 -Name Accounting Standards Codification -Section 65 -Paragraph 6 -Subparagraph (e) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480528/815-20-65-6 Reference 15: http://www.xbrl.org/2003/role/disclosureRef -Topic 815 -SubTopic 20 -Name Accounting Standards Codification -Section 65 -Paragraph 6 -Subparagraph (h)(1) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480528/815-20-65-6 Reference 16: http://www.xbrl.org/2003/role/disclosureRef -Topic 815 -SubTopic 20 -Name Accounting Standards Codification -Section 65 -Paragraph 6 -Subparagraph (h)(1)(i) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480528/815-20-65-6 Reference 17: http://www.xbrl.org/2003/role/disclosureRef -Topic 815 -SubTopic 20 -Name Accounting Standards Codification -Section 65 -Paragraph 6 -Subparagraph (h)(1)(iii) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480528/815-20-65-6 Reference 18: http://www.xbrl.org/2003/role/disclosureRef -Topic 815 -SubTopic 20 -Name Accounting Standards Codification -Section 65 -Paragraph 6 -Subparagraph (h)(1)(iv) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480528/815-20-65-6 Reference 19: http://www.xbrl.org/2003/role/disclosureRef -Topic 815 -SubTopic 20 -Name Accounting Standards Codification -Section 65 -Paragraph 6 -Subparagraph (i)(3) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480528/815-20-65-6 Reference 20: http://www.xbrl.org/2003/role/disclosureRef -Topic 105 -SubTopic 10 -Name Accounting Standards Codification -Section 65 -Paragraph 6 -Subparagraph (c) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479343/105-10-65-6 Reference 21: http://www.xbrl.org/2003/role/disclosureRef -Topic 105 -SubTopic 10 -Name Accounting Standards Codification -Section 65 -Paragraph 6 -Subparagraph (d) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479343/105-10-65-6 Reference 22: http://www.xbrl.org/2003/role/disclosureRef -Topic 944 -SubTopic 40 -Name Accounting Standards Codification -Section 65 -Paragraph 2 -Subparagraph (f)(1) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480016/944-40-65-2 Reference 23: http://www.xbrl.org/2003/role/disclosureRef -Topic 944 -SubTopic 40 -Name Accounting Standards Codification -Section 65 -Paragraph 2 -Subparagraph (f)(2) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480016/944-40-65-2 Reference 24: http://www.xbrl.org/2003/role/disclosureRef -Topic 740 -SubTopic 10 -Name Accounting Standards Codification -Section 65 -Paragraph 8 -Subparagraph (d)(2) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482615/740-10-65-8 Reference 25: http://www.xbrl.org/2003/role/disclosureRef -Topic 740 -SubTopic 10 -Name Accounting Standards Codification -Section 65 -Paragraph 8 -Subparagraph (d)(3) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482615/740-10-65-8 Reference 26: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 10 -Name Accounting Standards Codification -Section 65 -Paragraph 4 -Subparagraph (d) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479654/326-10-65-4 Reference 27: http://www.xbrl.org/2003/role/disclosureRef -Topic 250 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (b)(3) -Publisher FASB -URI https://asc.fasb.org/1943274/2147483443/250-10-50-1 Reference 28: http://www.xbrl.org/2003/role/disclosureRef -Topic 815 -SubTopic 40 -Name Accounting Standards Codification -Section 65 -Paragraph 1 -Subparagraph (e)(3) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480175/815-40-65-1 Reference 29: http://www.xbrl.org/2003/role/disclosureRef -Topic 250 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 7 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147483443/250-10-50-7 Reference 30: http://www.xbrl.org/2003/role/disclosureRef -Topic 220 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 5 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482765/220-10-50-5 Reference 31: http://www.xbrl.org/2003/role/disclosureRef -Topic 830 -SubTopic 30 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org/1943274/2147481674/830-30-50-1 Reference 32: http://www.xbrl.org/2003/role/disclosureRef -Topic 830 -SubTopic 30 -Name Accounting Standards Codification -Section 45 -Paragraph 17 -Publisher FASB -URI https://asc.fasb.org/1943274/2147481694/830-30-45-17 Reference 33: http://www.xbrl.org/2003/role/disclosureRef -Topic 830 -SubTopic 30 -Name Accounting Standards Codification -Section 45 -Paragraph 20 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481694/830-30-45-20 Reference 34: http://www.xbrl.org/2003/role/exampleRef -Topic 946 -SubTopic 830 -Name Accounting Standards Codification -Section 55 -Paragraph 11 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479168/946-830-55-11 Reference 35: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 205 -Name Accounting Standards Codification -Section 45 -Paragraph 3 -Publisher FASB -URI https://asc.fasb.org/1943274/2147478009/946-205-45-3 Reference 36: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 505 -Name Accounting Standards Codification -Section 50 -Paragraph 3 -Publisher FASB -URI https://asc.fasb.org/1943274/2147478448/946-505-50-3 Reference 37: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 210 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.6-04(19)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479170/946-210-S99-1 Reference 38: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 210 -Name Accounting Standards Codification -Section S99 -Paragraph 2 -Subparagraph (SX 210.6-05(4)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479170/946-210-S99-2 Reference 39: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 946 -SubTopic 220 -Name Accounting Standards Codification -Section S99 -Paragraph 3 -Subparagraph (SX 210.6-09(4)(b)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479134/946-220-S99-3 Reference 40: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 220 -Name Accounting Standards Codification -Section S99 -Paragraph 3 -Subparagraph (SX 210.6-09(6)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479134/946-220-S99-3 Reference 41: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 220 -Name Accounting Standards Codification -Section S99 -Paragraph 3 -Subparagraph (SX 210.6-09(7)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479134/946-220-S99-3 Reference 42: http://www.xbrl.org/2003/role/disclosureRef -Topic 505 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.3-04) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480008/505-10-S99-1 Reference 43: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 235 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.4-08(g)(1)(ii)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480678/235-10-S99-1 Reference 44: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 323 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 3 -Subparagraph (c) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481687/323-10-50-3 Reference 45: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 825 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 28 -Subparagraph (f) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482907/825-10-50-28 Reference 46: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 810 -SubTopic 10 -Section 45 -Paragraph 15 -Publisher FASB -URI https://asc.fasb.org/1943274/2147481231/810-10-45-15 Reference 47: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 810 -SubTopic 10 -Section 45 -Paragraph 16 -Publisher FASB -URI https://asc.fasb.org/1943274/2147481231/810-10-45-16 Reference 48: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 810 -SubTopic 10 -Section 55 -Paragraph 4I -Publisher FASB -URI https://asc.fasb.org/1943274/2147481175/810-10-55-4I Reference 49: http://www.xbrl.org/2003/role/disclosureRef -Topic 350 -SubTopic 60 -Name Accounting Standards Codification -Section 65 -Paragraph 1 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147476166/350-60-65-1 + Details
Name: | us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Details
Name: | us-gaap_DisposalGroupClassificationAxis=us-gaap_DisposalGroupDisposedOfBySaleNotDiscontinuedOperationsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis=mck_CanadianRetailDisposalGroupMember
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_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_DebtInstrumentAxis=mck_EuroDenominatedNotesMember
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=mck_FixedInterestRateSwapMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementEquityComponentsAxis=us-gaap_AociIncludingPortionAttributableToNoncontrollingInterestMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementEquityComponentsAxis=us-gaap_AccumulatedForeignCurrencyAdjustmentIncludingPortionAttributableToNoncontrollingInterestMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementEquityComponentsAxis=us-gaap_AccumulatedTranslationAdjustmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementEquityComponentsAxis=us-gaap_AccumulatedForeignCurrencyAdjustmentAttributableToNoncontrollingInterestMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementEquityComponentsAxis=mck_AOCIAccumulatedGainLossNetInvestmentHedgesIncludingNoncontrollingInterestMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementEquityComponentsAxis=mck_AOCIAccumulatedGainLossNetInvestmentHedgesNoncontrollingInterestMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementEquityComponentsAxis=mck_AOCIAccumulatedGainLossNetInvestmentHedgesPortionAttributableToParentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementEquityComponentsAxis=us-gaap_AccumulatedGainLossCashFlowHedgeIncludingNoncontrollingInterestMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementEquityComponentsAxis=us-gaap_AccumulatedGainLossNetCashFlowHedgeNoncontrollingInterestMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementEquityComponentsAxis=us-gaap_AccumulatedGainLossNetCashFlowHedgeParentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementEquityComponentsAxis=us-gaap_AccumulatedDefinedBenefitPlansAdjustmentNetGainLossIncludingPortionAttributableToNoncontrollingInterestMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementEquityComponentsAxis=us-gaap_AccumulatedDefinedBenefitPlansAdjustmentNetGainLossAttributableToNoncontrollingInterestMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementEquityComponentsAxis=us-gaap_AccumulatedDefinedBenefitPlansAdjustmentNetUnamortizedGainLossMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |