Investments in and Advances to Unconsolidated Affiliates - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2021	Mar. 31, 2020
Schedule Of Equity Method Investments [Line Items]
Distributions from unconsolidated affiliates	$ 0	$ 426
MGP BREIT Venture [Member]
Schedule Of Equity Method Investments [Line Items]
Distributions from unconsolidated affiliates	15,000	12,000
BetMGM [Member]
Schedule Of Equity Method Investments [Line Items]
Contributions to unconsolidated affiliates	$ 75,000	$ 20,000

Amount of distribution received from equity method investee for return of investment, classified as investing activities. Excludes distribution for return on investment, classified as operating activities.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 21D
-URI http://asc.fasb.org/extlink&oid=121586364&loc=SL94080555-108585

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 12
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=121586364&loc=d3e3179-108585

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration