Business Acquisition, Tender Offer, Percentage of Shares Tendered

No definition available.

Name:	mgm_BusinessAcquisitionTenderOfferPercentageOfSharesTendered
Namespace Prefix:	mgm_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	instant

- Definition

Business Acquisition, Tender Offer, Share Price

+ References

No definition available.

+ Details

Name:	mgm_BusinessAcquisitionTenderOfferSharePrice
Namespace Prefix:	mgm_
Data Type:	dtr-types:perShareItemType
Balance Type:	na
Period Type:	instant

- Definition

Business combination retaining ownership interest.

+ References

No definition available.

+ Details

Name:	mgm_BusinessCombinationRetainingOwnershipInterest
Namespace Prefix:	mgm_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Business Combination, Step Acquisition, Remaining Equity Interest In Acquiree To Be Acquired, Fair Value

+ References

No definition available.

+ Details

Name:	mgm_BusinessCombinationStepAcquisitionRemainingEquityInterestInAcquireeToBeAcquiredFairValue
Namespace Prefix:	mgm_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Decrease In Annual Rent Payment

+ References

No definition available.

+ Details

Name:	mgm_DecreaseInAnnualRentPayment
Namespace Prefix:	mgm_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Disposal Group, Including Discontinued Operation, Assets and Liabilities, Net

+ References

No definition available.

+ Details

Name:	mgm_DisposalGroupIncludingDiscontinuedOperationAssetsAndLiabilitiesNet
Namespace Prefix:	mgm_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Number Of Classes Of Common Stock

+ References

No definition available.

+ Details

Name:	mgm_NumberOfClassesOfCommonStock
Namespace Prefix:	mgm_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Operating partnership units received.

+ References

No definition available.

+ Details

Name:	mgm_OperatingPartnershipUnitsReceived
Namespace Prefix:	mgm_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Schedule of Business Acquisitions and Disposals [Line Items]

+ References

No definition available.

+ Details

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

- Definition

Percentage of voting equity interests acquired at the acquisition date in the business combination.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)
-URI https://asc.fasb.org/extlink&oid=79982066&loc=d3e1392-128463

+ Details

Name:	us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Price of a single share of a number of saleable stocks paid or offered to be paid in a business combination.

+ References

No definition available.

+ Details

Name:	us-gaap_BusinessAcquisitionSharePrice
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:perShareItemType
Balance Type:	na
Period Type:	instant

- Definition

Amount of consideration transferred, consisting of acquisition-date fair value of assets transferred by the acquirer, liabilities incurred by the acquirer, and equity interest issued by the acquirer.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 30
-Section 30
-Paragraph 8
-URI https://asc.fasb.org/extlink&oid=126966197&loc=d3e6613-128477

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 30
-Section 50
-Paragraph 1
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=126975305&loc=d3e6927-128479

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 30
-Section 30
-Paragraph 7
-URI https://asc.fasb.org/extlink&oid=126966197&loc=d3e6578-128477

+ Details

Name:	us-gaap_BusinessCombinationConsiderationTransferred1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of equity interests of the acquirer, including instruments or interests issued or issuable in consideration for the business combination.

+ References

+ Details

Name:	us-gaap_BusinessCombinationConsiderationTransferredEquityInterestsIssuedAndIssuable
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Percentage of equity in the acquiree held by the acquirer immediately before the acquisition date in a business combination.

+ References

No definition available.

+ Details

Name:	us-gaap_BusinessCombinationStepAcquisitionEquityInterestInAcquireePercentage
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Percent, after disposal, of ownership interest of a discontinued operation in which an equity method investment is retained.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 205
-SubTopic 20
-Section 50
-Paragraph 4B
-Subparagraph (d)(3)
-URI https://asc.fasb.org/extlink&oid=109222650&loc=SL51721665-107760

+ Details

Name:	us-gaap_DiscontinuedOperationEquityMethodInvestmentRetainedAfterDisposalOwnershipInterestAfterDisposal
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of consideration received or receivable for the disposal of assets and liabilities, including discontinued operation.

+ References

No definition available.

+ Details

Name:	us-gaap_DisposalGroupIncludingDiscontinuedOperationConsideration
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 323
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (a)(1)
-URI https://asc.fasb.org/extlink&oid=114001798&loc=d3e33918-111571

+ Details

Name:	us-gaap_EquityMethodInvestmentOwnershipPercentage
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

The net gain (loss) resulting from sales and other disposals of real estate owned for investment purposes.

+ 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 https://asc.fasb.org/extlink&oid=126954810&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)(9)(a))
-URI https://asc.fasb.org/extlink&oid=126953954&loc=SL114868664-224227

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 360
-Section 50
-Paragraph 1
-URI https://asc.fasb.org/extlink&oid=123605587&loc=d3e23528-158515

Reference 4: 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 https://asc.fasb.org/extlink&oid=126953954&loc=SL114868664-224227

Reference 5: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 220
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-04(14)(d))
-URI https://asc.fasb.org/extlink&oid=120399700&loc=SL114874048-224260

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 360
-Section 45
-Paragraph 4
-URI https://asc.fasb.org/extlink&oid=123605564&loc=d3e23439-158514

Reference 7: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 220
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-04(3)(a))
-URI https://asc.fasb.org/extlink&oid=120400993&loc=SL114874131-224263

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 360
-Section 45
-Paragraph 3
-URI https://asc.fasb.org/extlink&oid=123605564&loc=d3e23415-158514

+ Details

Name:	us-gaap_GainsLossesOnSalesOfInvestmentRealEstate
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The cash outflow associated with the acquisition of business during the period. The cash portion only of the acquisition price.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 30
-Section 50
-Paragraph 1
-Subparagraph (b)(1)
-URI https://asc.fasb.org/extlink&oid=126975305&loc=d3e6927-128479

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 13
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=126954810&loc=d3e3213-108585

+ Details

Name:	us-gaap_PaymentsToAcquireBusinessesGross
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The cash inflow associated with the amount received from the sale of a portion of the company's business, for example a segment, division, branch or other business, during the period.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 12
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=126954810&loc=d3e3179-108585

+ Details

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

- Definition

Number of shares issued in lieu of cash for services contributed to the entity. Number of shares includes, but is not limited to, shares issued for services contributed by vendors and founders.

+ References

No definition available.

+ Details

Name:	us-gaap_StockIssuedDuringPeriodSharesIssuedForServices
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_DisposalGroupClassificationAxis=us-gaap_DisposalGroupHeldforsaleNotDiscontinuedOperationsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis=mgm_TheMirageMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis=mgm_GoldStrikeTunicaMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

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

- Details

Name:	us-gaap_DisposalGroupClassificationAxis=us-gaap_DiscontinuedOperationsDisposedOfBySaleMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

Name:	srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis=mgm_MGMGrandLasVegasAndMandalayBayTransactionMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_BusinessAcquisitionAxis=mgm_LeoVegasMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

Name:	us-gaap_BusinessAcquisitionAxis=mgm_CosmopolitanOfLasVegasMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_BusinessAcquisitionAxis=mgm_MGPMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

ACQUISITIONS AND DIVESTITURES - Additional Information (Details) $ / shares in Units, $ in Thousands					1 Months Ended			3 Months Ended			4 Months Ended
	Feb. 15, 2023 USD ($)	Dec. 19, 2022 USD ($)	May 17, 2022 USD ($)	Apr. 29, 2022 USD ($) shares	Feb. 28, 2023 USD ($)	Dec. 31, 2022 USD ($)	Sep. 22, 2022 USD ($)	Jun. 30, 2023 USD ($)	Mar. 31, 2023 USD ($) commonStockClass	Mar. 31, 2022 USD ($)	Sep. 06, 2022 USD ($)	Sep. 07, 2022	May 02, 2022 kr / shares	Jul. 30, 2021 $ / shares
Schedule of Business Acquisitions and Disposals [Line Items]
Proceeds from sale of operating resorts									$ 452,824	$ 0
Disposal Group, Held-for-sale, Not Discontinued Operations \| The Mirage
Schedule of Business Acquisitions and Disposals [Line Items]
Decrease in annual rent payments						$ 90,000
Disposal Group, Held-for-sale, Not Discontinued Operations \| Gold Strike Tunica
Schedule of Business Acquisitions and Disposals [Line Items]
Decrease in annual rent payments					$ 40,000
VICI Properties, Inc
Schedule of Business Acquisitions and Disposals [Line Items]
Cash tender price				$ 4,400,000
Stock issued during period, issued for services (in shares) \| shares				1.366
Operating partnership units received (in shares) \| shares				1.366
Operating partnership units received (in shares)				1.00%
Ownership interest				$ 375,000
Affiliated Entity \| Discontinued Operations, Disposed of by Sale \| The Mirage
Schedule of Business Acquisitions and Disposals [Line Items]
Proceeds from sale of operating resorts		$ 1,075,000
Decrease in annual rent payments		90,000
Consideration received from sale of discontinued operations		$ 1,100,000
CNE \| Disposal Group, Held-for-sale, Not Discontinued Operations \| Gold Strike Tunica
Schedule of Business Acquisitions and Disposals [Line Items]
Proceeds from sale of operating resorts	$ 450,000
Decrease in annual rent payments	40,000
Gain (loss) on sale of real estate assets	398,000
Consideration received from sale of discontinued operations	473,000
Carrying value of assets and liabilities and comprehensive income	$ 75,000
MGM Grand Las Vegas and Mandalay Bay Transaction
Schedule of Business Acquisitions and Disposals [Line Items]
Number of classes of common stock \| commonStockClass									2
Ownership interest (in percent)									50.10%
LeoVegas
Schedule of Business Acquisitions and Disposals [Line Items]
Shares tendered (in percent)													1
Tender offer price (in krona per share) \| kr / shares													kr 61
Ownership interest acquired (in percent)							2.00%					65.00%
Cash tender price							$ 370,000
Operating partnership equity interest (in percent)												31.00%
Equity interests issued and issuable											$ 172,000
LeoVegas \| Subsequent Event
Schedule of Business Acquisitions and Disposals [Line Items]
Remaining outstanding shares, fair value								$ 11,000
Cosmopolitan of Las Vegas
Schedule of Business Acquisitions and Disposals [Line Items]
Ownership interest acquired (in percent)			100.00%
Cash tender price			$ 1,700,000
Cash consideration for acquisition			$ 1,625,000
MGP \| VICI Properties, Inc
Schedule of Business Acquisitions and Disposals [Line Items]
Fixed exchange ratio (in dollars per share) \| $ / shares														$ 43