Investments in and Advances to Unconsolidated Affiliates - Schedule of Share of Income (Loss) From Unconsolidated Affiliates (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Schedule Of Equity Method Investments [Line Items]
Income (loss) from unconsolidated affiliates	$ (25,579)	$ 35,748
CityCenter Holdings LLC As Investee [Member]
Schedule Of Equity Method Investments [Line Items]
Income (loss) from unconsolidated affiliates	(2,831)	20,666
MGP BREIT Venture [Member]
Schedule Of Equity Method Investments [Line Items]
Income (loss) from unconsolidated affiliates	38,962	19,950
BetMGM [Member]
Schedule Of Equity Method Investments [Line Items]
Income (loss) from unconsolidated affiliates	(59,236)	(10,677)
Other [Member]
Schedule Of Equity Method Investments [Line Items]
Income (loss) from unconsolidated affiliates	$ (2,474)	$ 5,809