Annual rent escalator after year fifteen.

No definition available.

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Period Type:	duration

- Definition

Annual rent escalator after year twenty.

+ References

No definition available.

+ Details

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Namespace Prefix:	mgm_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Annual rent escalator cap after year fifteen.

+ References

No definition available.

+ Details

Name:	mgm_AnnualRentEscalatorCapAfterYearFifteen
Namespace Prefix:	mgm_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Annual rent escalator cap from year eleven through year twenty.

+ References

No definition available.

+ Details

Name:	mgm_AnnualRentEscalatorCapFromYearElevenThroughYearTwenty
Namespace Prefix:	mgm_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Annual rent escalator from year eleven through year twenty.

+ References

No definition available.

+ Details

Name:	mgm_AnnualRentEscalatorFromYearElevenThroughYearTwenty
Namespace Prefix:	mgm_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Annual rent escalator from year one through year fifteen.

+ References

No definition available.

+ Details

Name:	mgm_AnnualRentEscalatorFromYearOneThroughYearFifteen
Namespace Prefix:	mgm_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Annual rent escalator from year one through year ten.

+ References

No definition available.

+ Details

Name:	mgm_AnnualRentEscalatorFromYearOneThroughYearTen
Namespace Prefix:	mgm_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Lease, initial annual rent, beginning period.

+ References

No definition available.

+ Details

Name:	mgm_LeaseInitialAnnualRentBeginningPeriod
Namespace Prefix:	mgm_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Definition

Leases.

+ References

No definition available.

+ Details

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Namespace Prefix:	mgm_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of renewal periods, exercisable at option.

+ References

No definition available.

+ Details

Name:	mgm_NumberOfRenewalPeriodsExercisableAtOption
Namespace Prefix:	mgm_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of rent expense incurred for leased assets, including but not limited to, furniture and equipment, that is not directly or indirectly associated with the manufacture, sale or creation of a product or product line.

+ References

No definition available.

+ Details

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

- Definition

Term of lessee's operating lease renewal, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 20
-Section 50
-Paragraph 3
-Subparagraph (a)(3)
-URI http://asc.fasb.org/extlink&oid=121609121&loc=SL77918673-209980

+ Details

Name:	us-gaap_LesseeOperatingLeaseRenewalTerm
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	instant

- Definition

Term of lessee's operating lease, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

+ References

+ Details

Name:	us-gaap_LesseeOperatingLeaseTermOfContract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	instant

- Details

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

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=mgm_LasVegasStripResortsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_SubsegmentsAxis=mgm_BellagioMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=mgm_MGPBREITVentureMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_SubsegmentsAxis=mgm_MandalayBayAndMGMGrandLasVegasMember
Namespace Prefix:
Data Type:	na
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Period Type:

Leases - Additional Information (Detail) $ in Millions			6 Months Ended
Leases - Additional Information (Detail) $ in Millions	Mar. 01, 2021 USD ($)	Dec. 01, 2020 USD ($)	Jun. 30, 2021 Renewal_period
Blackstone Real Estate Income Trust [Member] \| Las Vegas Strip Resorts [Member] \| Bellagio BREIT Venture [Member]
Leases [Line Items]
Lease agreement initial lease term			30 years
Lease, initial annual rent, beginning period			Nov. 15, 2019
Number of renewal periods, exercisable at option \| Renewal_period			2
Lease agreement renewal period			10 years
Annual rent escalator from year one through year ten			2.00%
Annual rent escalator from year eleven through year twenty			2.00%
Annual rent escalator cap from year eleven through year twenty			3.00%
Annual rent escalator after year twenty			4.00%
Annual rent \| $		$ 250
MGP BREIT Venture [Member] \| Mandalay Bay and MGM Grand Las Vegas [Member]
Leases [Line Items]
Lease agreement initial lease term			30 years
Lease, initial annual rent, beginning period			Feb. 14, 2020
Number of renewal periods, exercisable at option \| Renewal_period			2
Lease agreement renewal period			10 years
Annual rent \| $	$ 298
Annual rent escalator from year one through year fifteen			2.00%
Annual rent escalator after year fifteen			2.00%
Annual rent escalator cap after year fifteen			3.00%