GOODWILL AND OTHER INTANGIBLE ASSETS - Schedule of Changes in Goodwill (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
Sep. 30, 2023	Dec. 31, 2022
Goodwill [Roll Forward]
Goodwill, beginning balance	$ 5,029,312	$ 3,480,997
Acquisitions/Divestitures	125,612	1,567,586
Reclassifications	0	(40,523)
Currency exchange	(12,086)	21,252
Goodwill, ending balance	5,142,838	5,029,312
Reportable segments \| Las Vegas Strip Resorts
Goodwill [Roll Forward]
Goodwill, beginning balance	2,707,009	1,427,790
Acquisitions/Divestitures	0	1,279,219
Reclassifications	0	0
Currency exchange	0	0
Goodwill, ending balance	2,707,009	2,707,009
Reportable segments \| Regional Operations
Goodwill [Roll Forward]
Goodwill, beginning balance	660,940	701,463
Acquisitions/Divestitures	0	0
Reclassifications	0	(40,523)
Currency exchange	0	0
Goodwill, ending balance	660,940	660,940
Reportable segments \| MGM China
Goodwill [Roll Forward]
Goodwill, beginning balance	1,350,878	1,351,744
Acquisitions/Divestitures	0	0
Reclassifications	0	0
Currency exchange	(5,011)	(866)
Goodwill, ending balance	1,345,867	1,350,878
Corporate and other
Goodwill [Roll Forward]
Goodwill, beginning balance	310,485	0
Acquisitions/Divestitures	125,612	288,367
Reclassifications	0	0
Currency exchange	(7,075)	22,118
Goodwill, ending balance	$ 429,022	$ 310,485

Goodwill, Acquired During Period, Net of Written off Related to Sale of Business Unit

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- Definition

Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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- Definition

Amount of foreign currency translation gain (loss) which increases (decreases) an asset representing future economic benefits from other assets acquired in a business combination that are not individually identified and separately recognized.

+ References

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- Definition

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

+ References

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Amount of transfers into (out of) an asset representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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