| Document and Entity Information | Jun. 30, 2021 |
| Cover [Abstract] | |
| Entity Incorporation State Country Code | DE |
| Amendment Flag | false |
| Entity Central Index Key | 0000789570 |
| Document Type | 8-K |
| Document Period End Date | Jun. 30, 2021 |
| Entity Registrant Name | MGM RESORTS INTERNATIONAL |
| Entity File Number | 001-10362 |
| Entity Tax Identification Number | 88-0215232 |
| Entity Address, Address Line One | 3600 Las Vegas Boulevard South |
| Entity Address, City or Town | Las Vegas |
| Entity Address, State or Province | NV |
| Entity Address, Postal Zip Code | 89109 |
| City Area Code | (702) |
| Local Phone Number | 693-7120 |
| Written Communications | false |
| Soliciting Material | false |
| Pre Commencement Tender Offer | false |
| Pre Commencement Issuer Tender Offer | false |
| Security 12b Title | Common stock (Par Value $0.01) |
| Trading Symbol | MGM |
| Security Exchange Name | NYSE |
| Entity Emerging Growth Company | false |
