amount of time in which cash flow hedge gain (loss) will be reclassified to the income statement

No definition available.

Name:	tap_Cashflowhedgegainlosstobereclassifiedwithintwelvemonthsterm
Namespace Prefix:	tap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Derivative, Strike Price

+ References

No definition available.

+ Details

Name:	tap_DerivativeStrikePrice
Namespace Prefix:	tap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	instant

- Definition

Proceeds from the Termination and cash Settlement of Derivatives

+ References

No definition available.

+ Details

Name:	tap_ProceedsfromtheTerminationandcashSettlementofDerivatives
Namespace Prefix:	tap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Face (par) amount of debt instrument at time of issuance.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=114775744&loc=d3e28551-108399

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=114775985&loc=d3e28878-108400

+ Details

Name:	us-gaap_DebtInstrumentFaceAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22(a)(1))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

Name:	us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Fixed interest rate related to the interest rate derivative.

+ References

No definition available.

+ Details

Name:	us-gaap_DerivativeFixedInterestRate
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Nominal or face amount used to calculate payment on derivative.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 1B
-URI http://asc.fasb.org/extlink&oid=109980867&loc=SL5580258-113959

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 1A
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=109980867&loc=SL5579245-113959

+ Details

Name:	us-gaap_DerivativeNotionalAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	instant

- Definition

Maximum length of time over which the entity is hedging its exposure to the variability in future cash flows for forecasted transactions, excluding those forecasted transactions related to the payment of variable interest on existing financial instruments, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 30
-Section 50
-Paragraph 1
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=112277219&loc=d3e80748-113994

+ Details

Name:	us-gaap_MaximumLengthOfTimeHedgedInCashFlowHedge1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
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_ScheduleOfTradingSecuritiesAndOtherTradingAssetsLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	srt_StatementScenarioAxis=srt_ScenarioForecastMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LongtermDebtTypeAxis=us-gaap_SeniorNotesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=tap_A1.0billion2.10notesdue2021Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=tap_A500million2.25notesdue2021Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

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

- Details

Name:	srt_ConsolidatedEntitiesAxis=srt_ParentCompanyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Derivative Instruments and Hedging Activities Narrative (Details) € in Millions, $ in Millions	12 Months Ended		49 Months Ended
	Sep. 30, 2020	Apr. 03, 2019 USD ($)	Jul. 15, 2022	Apr. 03, 2019 EUR (€)	Mar. 20, 2019 USD ($)	Mar. 20, 2019 EUR (€)	Oct. 04, 2018 $ / shares	Apr. 18, 2018 USD ($)	Mar. 15, 2017 USD ($)	May 03, 2012 USD ($)
Forecast [Member]
Schedule of Trading Securities and Other Trading Assets
Term for expected gains recorded in AOCI	12 months
Maximum term of time in cash flow hedge			4 years
Senior Notes [Member]
Schedule of Trading Securities and Other Trading Assets
Debt Instrument, Face Amount										$ 1,900.0
$1.0 billion 2.10% notes due 2021 [Member] \| Senior Notes [Member]
Schedule of Trading Securities and Other Trading Assets
Debt Instrument, Face Amount									$ 1,000.0
$500 million 2.25% notes due 2020 [Member] \| Senior Notes [Member]
Schedule of Trading Securities and Other Trading Assets
Debt Instrument, Interest Rate, Stated Percentage									2.25%
Debt Instrument, Face Amount								$ 500.0
Cross currency swaps
Schedule of Trading Securities and Other Trading Assets
Derivative, Notional Amount		$ 500.0		€ 445	$ 400.0	€ 353
Cross currency swaps \| $1.0 billion 2.10% notes due 2021 [Member]
Schedule of Trading Securities and Other Trading Assets
Derivative, Fixed Interest Rate					0.71%	0.71%
Cross currency swaps \| $500 million 2.25% notes due 2020 [Member]
Schedule of Trading Securities and Other Trading Assets
Derivative, Fixed Interest Rate					0.68%	0.68%		0.85%
Proceeds from the Termination and cash Settlement of Derivatives		$ 47.0
Warrant [Member]
Schedule of Trading Securities and Other Trading Assets
Derivative, Price Risk Option Strike Price \| $ / shares							$ 6.00
Parent Company [Member] \| $1.0 billion 2.10% notes due 2021 [Member] \| Senior Notes [Member]
Schedule of Trading Securities and Other Trading Assets
Debt Instrument, Interest Rate, Stated Percentage									2.10%
Debt Instrument, Face Amount									$ 1,000.0
Parent Company [Member] \| $500 million 2.25% notes due 2020 [Member] \| Senior Notes [Member]
Schedule of Trading Securities and Other Trading Assets
Debt Instrument, Interest Rate, Stated Percentage									2.25%
Debt Instrument, Face Amount									$ 500.0