XML 73 R57.htm IDEA: XBRL DOCUMENT
v3.21.1

Investment in Change Healthcare Joint Venture - Net Gain on Split-off of Change Healthcare JV (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions |  | 12 Months Ended
--- | --- | ---
Mar. 09, 2020 | Mar. 31, 2021 | Mar. 31, 2020 | Mar. 31, 2019
Schedule of Equity Method Investments [Line Items] |  |  |  |
Net gain on split-off of the Change Healthcare JV |  | $ 0 | $ 0 | $ 56
Separation of Change Healthcare JV |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |
Shares of common stock exchanged (shares) | 15.4 |  |  |
Change Healthcare |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |
Fair value of McKesson common stock accepted (15.4 million shares at $131.97 per share on March 9, 2020) | $ 2,036 |  |  |
Investment in the Change Healthcare JV at exchange date | (2,096) |  |  |
Reversal of deferred tax liability | 521 |  |  |
Release of accumulated other comprehensive attributable to the joint venture | (24) |  |  |
Less: Transaction costs incurred | (23) |  |  |
Net gain on split-off of the Change Healthcare JV | $ 414 |  |  |
Shares repurchased (in shares) | 15.4 |  |  |
Cost of shares repurchased (in usd per share) | $ 131.97 |  |  |

X
- Definition Equity Method Investment, Carrying Amount + References No definition available. + Details
Name: | mck_EquityMethodInvestmentCarryingAmount
Namespace Prefix: | mck_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Equity Method Investment, Fair Value of Stock Accepted + References No definition available. + Details
Name: | mck_EquityMethodInvestmentFairValueofStockAccepted
Namespace Prefix: | mck_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Equity Method Investment, Release of Accumulated Other Comprehensive income (Loss) + References No definition available. + Details
Name: | mck_EquityMethodInvestmentReleaseofAccumulatedOtherComprehensiveincomeLoss
Namespace Prefix: | mck_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Equity Method Investment, Stock Accepted + References No definition available. + Details
Name: | mck_EquityMethodInvestmentStockAccepted
Namespace Prefix: | mck_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition Equity Method Investment, Stock Accepted, Average Cost + References No definition available. + Details
Name: | mck_EquityMethodInvestmentStockAcceptedAverageCost
Namespace Prefix: | mck_
Data Type: | num:perShareItemType
Balance Type: | na
Period Type: | duration

X
- Definition Equity Method Investment, Transaction Costs Incurred + References No definition available. + Details
Name: | mck_EquityMethodInvestmentTransactionCostsIncurred
Namespace Prefix: | mck_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Equity Method Investments, Reversal of Deferred Tax Liability + References No definition available. + Details
Name: | mck_EquityMethodInvestmentsReversalofDeferredTaxLiability
Namespace Prefix: | mck_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Exchange Offer, Shares Exchanged + References No definition available. + Details
Name: | mck_ExchangeOfferSharesExchanged
Namespace Prefix: | mck_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of gain (loss) on sale or disposal of an equity method investment. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=121586364&loc=d3e3602-108585 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03(b)(7)(c)) -URI http://asc.fasb.org/extlink&oid=120395209&loc=SL114868664-224227 Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03(b)(9)(a)) -URI http://asc.fasb.org/extlink&oid=120395209&loc=SL114868664-224227 + Details
Name: | us-gaap_EquityMethodInvestmentRealizedGainLossOnDisposal
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
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 No definition available. + Details
Name: | us-gaap_ScheduleOfEquityMethodInvestmentsLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_ConversionOfStockByUniqueDescriptionAxis=mck_SeparationofChangeHealthcareJVMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis=mck_ChangeHealthcareLLCChangeHealthcareMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |