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Investments in and Advances to Unconsolidated Affiliates - Schedule of Investments in and Advances to Unconsolidated Affiliates (Detail) - USD ($) $ in Thousands | Sep. 30, 2021 | Dec. 31, 2020
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Schedule Of Equity Method Investments [Line Items] |  |
Investments in and advances to unconsolidated affiliates | $ 941,145 | $ 1,447,043
City Center |  |
Schedule Of Equity Method Investments [Line Items] |  |
Percentage ownership interest |  | 50.00%
Investments in and advances to unconsolidated affiliates | $ 0 | $ 441,893
MGP BREIT Venture |  |
Schedule Of Equity Method Investments [Line Items] |  |
Percentage ownership interest | 50.10% | 50.10%
Investments in and advances to unconsolidated affiliates | $ 815,399 | $ 810,066
BetMGM |  |
Schedule Of Equity Method Investments [Line Items] |  |
Percentage ownership interest | 50.00% | 50.00%
Investments in and advances to unconsolidated affiliates | $ 22,983 | $ 27,310
Other |  |
Schedule Of Equity Method Investments [Line Items] |  |
Investments in and advances to unconsolidated affiliates | $ 102,763 | $ 167,774

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