Investments in and Advances to Unconsolidated Affiliates - Schedule of Investments in and Advances to Unconsolidated Affiliates (Detail) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Schedule Of Equity Method Investments [Line Items]
Investments in and advances to unconsolidated affiliates	$ 1,439,454	$ 1,447,043
CityCenter Holdings LLC As Investee [Member]
Schedule Of Equity Method Investments [Line Items]
Investments in and advances to unconsolidated affiliates	432,781	441,893
MGP BREIT Venture [Member]
Schedule Of Equity Method Investments [Line Items]
Investments in and advances to unconsolidated affiliates	820,390	810,066
BetMGM [Member]
Schedule Of Equity Method Investments [Line Items]
Investments in and advances to unconsolidated affiliates	43,054	27,310
Other [Member]
Schedule Of Equity Method Investments [Line Items]
Investments in and advances to unconsolidated affiliates	$ 143,229	$ 167,774