EMPLOYEE BENEFIT PLANS - Schedule of Table Outlining Company's Participation in Pension Plans (Details) $ in Thousands	12 Months Ended
Dec. 31, 2025 USD ($) agreement	Dec. 31, 2024 USD ($)	Dec. 31, 2023 USD ($)
Multiemployer Plans [Line Items]
EIN/Pension Plan Number	88-0215232
Number of collective bargaining agreements \| agreement	11
Number of significant collective bargaining agreements, covering more than two-thirds of participants \| agreement	5
Western Unite Here and Employers Pension Fund
Multiemployer Plans [Line Items]
EIN/Pension Plan Number	93-4160766
Pension Protection Act Zone Status		Green	Green
FIP/RP Status	No
Contributions by the Company \| $	$ 63,757	$ 61,630	$ 59,172
Surcharge Imposed	No
Minimum percentage of total contributions to be listed in Pension Plan's Forms 5500		5.00%	5.00%
The Legacy Plan of the UNITE HERE Retirement Fund (UHF)
Multiemployer Plans [Line Items]
EIN/Pension Plan Number	82-0994119
Pension Protection Act Zone Status		Red	Red
FIP/RP Status	Implemented
Contributions by the Company \| $	$ 10,657	$ 10,448	$ 10,113
Surcharge Imposed	No
Minimum percentage of total contributions to be listed in Pension Plan's Forms 5500		5.00%	5.00%

The Tax Identification Number (TIN), also known as an Employer Identification Number (EIN), is a unique 9-digit value assigned by the IRS.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Exchange Act
-Number 240
-Section 12
-Subsection b-2

+ Details

Name:	dei_EntityTaxIdentificationNumber
Namespace Prefix:	dei_
Data Type:	dei:employerIdItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the number of collective bargaining agreements that require contributions to the Pension Plan.

+ References

No definition available.

+ Details

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

- Definition

Multiemployer plans, number of significant collective bargaining agreements in which more than half of the company's employees are participants.

+ References

No definition available.

+ Details

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

- Definition

Indicates certified zone status of multiemployer pension plan determined to be individually significant. Acceptable values are "Green", "Yellow", "Orange", "Red", "Other", and "NA".

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 715
-SubTopic 80
-Name Accounting Standards Codification
-Section 55
-Paragraph 8
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480547/715-80-55-8

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 80
-Name Accounting Standards Codification
-Section 50
-Paragraph 5
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480576/715-80-50-5

+ Details

Name:	us-gaap_MultiemployerPlanPensionSignificantCertifiedZoneStatusFixedList
Namespace Prefix:	us-gaap_
Data Type:	us-types:zoneStatusItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of cost for employer contribution to multiemployer pension plan determined to be individually significant.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 715
-SubTopic 80
-Name Accounting Standards Codification
-Section 55
-Paragraph 8
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480547/715-80-55-8

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 80
-Name Accounting Standards Codification
-Section 50
-Paragraph 5
-Subparagraph (e)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480576/715-80-50-5

+ Details

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

- Definition

Percentage of employer contribution required by collective-bargaining arrangement (CBA) to total contribution from all participating employers in multiemployer pension plan determined to be individually significant.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 715
-SubTopic 80
-Name Accounting Standards Codification
-Section 50
-Paragraph 5
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480576/715-80-50-5

+ Details

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

- Definition

Indicates whether funding improvement plan or rehabilitation plan was implemented or pending for multiemployer pension plan, determined to be individually significant. Acceptable values are "No", "Pending", "Implemented", "Other", and "NA".

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 715
-SubTopic 80
-Name Accounting Standards Codification
-Section 55
-Paragraph 8
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480547/715-80-55-8

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 80
-Name Accounting Standards Codification
-Section 50
-Paragraph 5
-Subparagraph (f)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480576/715-80-50-5

+ Details

Name:	us-gaap_MultiemployerPlanPensionSignificantFundingImprovementOrRehabilitationPlanImplementationStatusFixedList
Namespace Prefix:	us-gaap_
Data Type:	us-types:fundingImprovementAndRehabilitationPlanItemType
Balance Type:	na
Period Type:	duration

- Definition

Indicates whether employer paid surcharge to multiemployer pension plan determined to be individually significant. Acceptable values are "No", "Yes", and "NA".

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 715
-SubTopic 80
-Name Accounting Standards Codification
-Section 55
-Paragraph 8
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480547/715-80-55-8

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 80
-Name Accounting Standards Codification
-Section 50
-Paragraph 5
-Subparagraph (f)(2)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480576/715-80-50-5

+ Details

Name:	us-gaap_MultiemployerPlanPensionSignificantSurchargeFixedList
Namespace Prefix:	us-gaap_
Data Type:	us-types:surchargeItemType
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

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 715
-SubTopic 80
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480576/715-80-50-6

Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Topic 715
-SubTopic 80
-Name Accounting Standards Codification
-Section 50
-Paragraph 11
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480576/715-80-50-11

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 80
-Name Accounting Standards Codification
-Section 50
-Paragraph 5
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480576/715-80-50-5

Reference 4: http://www.xbrl.org/2003/role/exampleRef
-Topic 715
-SubTopic 80
-Name Accounting Standards Codification
-Section 50
-Paragraph 11
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480576/715-80-50-11

Reference 5: http://www.xbrl.org/2003/role/exampleRef
-Topic 715
-SubTopic 80
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480576/715-80-50-6

Reference 6: http://www.xbrl.org/2003/role/exampleRef
-Topic 715
-SubTopic 80
-Name Accounting Standards Codification
-Section 50
-Paragraph 11
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480576/715-80-50-11

Reference 7: http://www.xbrl.org/2003/role/exampleRef
-Topic 715
-SubTopic 80
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480576/715-80-50-6

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 80
-Name Accounting Standards Codification
-Section 50
-Paragraph 5
-Subparagraph (f)(3)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480576/715-80-50-5

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 80
-Name Accounting Standards Codification
-Section 50
-Paragraph 11
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480576/715-80-50-11

Reference 10: http://www.xbrl.org/2003/role/exampleRef
-Topic 715
-SubTopic 80
-Name Accounting Standards Codification
-Section 55
-Paragraph 8
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480547/715-80-55-8

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 80
-Name Accounting Standards Codification
-Section 35
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480606/715-80-35-1

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 80
-Name Accounting Standards Codification
-Section 50
-Paragraph 5
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480576/715-80-50-5

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 80
-Name Accounting Standards Codification
-Section 50
-Paragraph 5
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480576/715-80-50-5

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 80
-Name Accounting Standards Codification
-Section 50
-Paragraph 5
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480576/715-80-50-5

Reference 15: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 80
-Name Accounting Standards Codification
-Section 50
-Paragraph 5
-Subparagraph (e)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480576/715-80-50-5

Reference 16: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 80
-Name Accounting Standards Codification
-Section 50
-Paragraph 5
-Subparagraph (e)(2)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480576/715-80-50-5

Reference 17: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 80
-Name Accounting Standards Codification
-Section 50
-Paragraph 5
-Subparagraph (f)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480576/715-80-50-5

Reference 18: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 80
-Name Accounting Standards Codification
-Section 50
-Paragraph 5
-Subparagraph (f)(2)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480576/715-80-50-5

Reference 19: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 80
-Name Accounting Standards Codification
-Section 50
-Paragraph 9
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480576/715-80-50-9

+ Details

Name:	us-gaap_MultiemployerPlansLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_RetirementPlanNameAxis=mgm_WesternUniteHereAndEmployersPensionFundMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RetirementPlanNameAxis=mgm_LegacyPlanOfUNITEHERERetirementFundMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: