Summary of Significant Accounting Policies	6 Months Ended
Jun. 30, 2018
Accounting Policies [Abstract]
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Basis of presentation. The accompanying condensed consolidated financial statements have been prepared in accordance with U.S. generally accepted accounting principles (“U.S. GAAP”) for interim financial information set forth in the Accounting Standards Codification (“ASC”), as published by the Financial Accounting Standards Board (“FASB”), and with the applicable rules and regulations of the Securities and Exchange Commission (“SEC”). Accordingly, they do not include all of the information and footnotes required by U.S. GAAP for complete financial statements. All adjustments (consisting of normal recurring accruals) considered necessary for a fair statement of results for the interim period have been included. Certain reclassifications have been made to conform the prior period presentation. Property tax expense was separately classified in prior periods and is now classified within “reimbursable expenses” in the accompanying condensed consolidated statements of operations. The accompanying condensed consolidated financial statements and related notes should be read in conjunction with the audited financial statements and notes thereto included in the Company's most recent Annual Report on Form 10-K. Variable Interest Entities. The condensed consolidated financial statements of MGP include the accounts of the Operating Partnership, a VIE of which the Company is the primary beneficiary, as well as its wholly owned and majority-owned subsidiaries. MGP’s maximum exposure to loss is the carrying value of the assets and liabilities of the Operating Partnership, which represents all of MGP’s assets and liabilities. As MGP holds what is deemed a majority voting interest in the Operating Partnership through its ownership of the Operating Partnership’s sole general partner, it qualifies for the exemption from providing certain of the required disclosures associated with investments in VIEs. The condensed consolidated financial statements of the Operating Partnership include the accounts of its wholly owned subsidiary, the Landlord, which owns the real estate, a VIE of which the Operating Partnership is the primary beneficiary. As of June 30, 2018, on a consolidated basis the Landlord had total assets of $9.9 billion primarily related to its real estate assets, and total liabilities of $227 million primarily related to its deferred revenue and above market lease liability. Noncontrolling interest. The Company presents noncontrolling interest and classifies such interest as a component of consolidated shareholders’ equity, separate from the Company’s Class A shareholders’ equity. Noncontrolling interest in the Company represents Operating Partnership units currently held by subsidiaries of MGM. Net income or loss of the Operating Partnership is allocated to its noncontrolling interest based on the noncontrolling interest’s ownership percentage in the Operating Partnership except for income tax expenses. Ownership percentage is calculated by dividing the number of Operating Partnership units held by the noncontrolling interest by the total Operating Partnership units held by the noncontrolling interest and the Company. Issuance of additional Class A shares and Operating Partnership units changes the ownership interests of both the noncontrolling interest and the Company. Such transactions and the related proceeds are treated as capital transactions. MGM may tender its Operating Partnership units for redemption by the Operating Partnership in exchange for cash equal to the market price of MGP’s Class A shares at the time of redemption or for unregistered Class A shares on a one-for-one basis. Such selection to pay cash or issue Class A shares to satisfy an Operating Partnership unitholder’s redemption request is solely within the control of MGP’s independent conflicts committee. Real estate investments. Real estate investments consist of land, buildings, improvements and integral equipment. The contribution or acquisition of the real property by the Operating Partnership from MGM represent transactions between entities under common control, and as a result, such real estate was initially recorded by the Company at MGM’s historical cost basis, less accumulated depreciation (i.e., there was no change in the basis of the contributed assets), as of the contribution or acquisition dates. Costs of maintenance and repairs to real estate investments are the responsibility of the Tenant under the Master Lease. Although the Tenant is responsible for all capital expenditures during the term of the Master Lease, if, in the future, a deconsolidation event occurs, the Company will be required to pay the Tenant, should the Tenant so elect, for certain capital improvements that would not constitute “normal tenant improvements” in accordance with U.S. GAAP (“Non-Normal Tenant Improvements”), subject to an initial cap of $100 million in the first year of the Master Lease increasing annually by $75 million each year thereafter. The Company will be entitled to receive additional rent based on the 10-year Treasury yield plus 600 basis points multiplied by the value of the new capital improvements the Company is required to pay for in connection with a deconsolidation event and such capital improvements will be subject to the terms of the Master Lease. Examples of Non-Normal Tenant Improvements include the costs of structural elements at the properties, including capital improvements that expand the footprint or square footage of any of the properties or extend the useful life of the properties, as well as equipment that would be a necessary improvement at any of the properties, including initial installation of elevators, air conditioning systems or electrical wiring. Such Non-Normal Tenant Improvements are capitalized and depreciated over the asset’s remaining life. Inception-to-date Non-Normal Tenant Improvements were $138.9 million through June 30, 2018. Deferred revenue. The Company receives nonmonetary consideration related to Non-Normal Tenant Improvements as they become MGP’s property pursuant to the Master Lease, and recognizes the cost basis of Non-Normal Tenant Improvements as real estate investments and deferred revenue. The Company depreciates the real estate investments over their estimated useful lives and amortizes the deferred revenue as additional rental revenue over the remaining term of the Master Lease once the related real estate assets are placed in service. Income tax provision. For interim income tax reporting the Company estimates its annual effective tax rate and applies it to its year-to-date ordinary income. The tax effects of unusual or infrequently occurring items, including changes in judgment about valuation allowances and effects of changes in tax laws or rates, are reported in the interim period in which they occur. The Company’s effective income tax rate was 2.6% and 2.3% for the three and six months ended June 30, 2018, respectively. The provision for current taxes and the deferred tax liability in the accompanying financial statements are attributable to noncontrolling interest since the payment of such taxes are the responsibility of MGM. Recently issued accounting standards. In August 2017, the FASB issued Accounting Standards Update No. 2017-12, Derivatives and Hedging (Topic 815): Targeted Improvements to Accounting for Hedging Activities (“ASU 2017-12”). ASU 2017-12 is effective for fiscal years beginning after December 15, 2018, and interim periods within those years. ASU 2017-12 amends the hedge accounting recognition and presentation requirements in order to improve the transparency and understandability of information about an entity’s risk management activities, and simplifies the application of hedge accounting. The Company is currently assessing the impact that adoption of this guidance will have on its consolidated financial statements and footnote disclosures. In 2016 and 2018, the FASB issued ASC 842 “Leases (Topic 842),” which replaces the existing guidance in ASC 840, “Leases.” ASC 842 is effective for fiscal years, and interim periods within those years, beginning after December 15, 2018. ASC 842 requires a dual approach for lessee accounting under which a lessee would account for leases as finance leases or operating leases. Both finance leases and operating leases will result in the lessee recognizing a right-of-use (“ROU”) asset and a corresponding lease liability. For finance leases, the lessee would recognize interest expense and amortization of the ROU asset and for operating leases the lessee would recognize a straight-line total lease expense. The Company is currently assessing the impact the adoption of ASC 842 will have on its consolidated financial statements and footnote disclosures. In May 2014, the FASB issued ASC 606, Revenue from Contracts with Customers (Topic 606) which outlines a new, single comprehensive model for entities to use in accounting for revenue arising from contracts with customers and supersedes most current revenue recognition guidance, including industry-specific guidance. Under the standard, revenue is recognized when a customer obtains control of promised goods or services in an amount that reflects the consideration the entity expects to receive in exchange for those goods and services. The Company adopted ASC 606 on January 1, 2018 and it did not have a material impact on the Company’s financial statements and footnote disclosures.

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

Basis of presentation. The accompanying condensed consolidated financial statements have been prepared in accordance with U.S. generally accepted accounting principles (“U.S. GAAP”) for interim financial information set forth in the Accounting Standards Codification (“ASC”), as published by the Financial Accounting Standards Board (“FASB”), and with the applicable rules and regulations of the Securities and Exchange Commission (“SEC”). Accordingly, they do not include all of the information and footnotes required by U.S. GAAP for complete financial statements. All adjustments (consisting of normal recurring accruals) considered necessary for a fair statement of results for the interim period have been included. Certain reclassifications have been made to conform the prior period presentation. Property tax expense was separately classified in prior periods and is now classified within “reimbursable expenses” in the accompanying condensed consolidated statements of operations.

The accompanying condensed consolidated financial statements and related notes should be read in conjunction with the audited financial statements and notes thereto included in the Company's most recent Annual Report on Form 10-K.

Variable Interest Entities. The condensed consolidated financial statements of MGP include the accounts of the Operating Partnership, a VIE of which the Company is the primary beneficiary, as well as its wholly owned and majority-owned subsidiaries. MGP’s maximum exposure to loss is the carrying value of the assets and liabilities of the Operating Partnership, which represents all of MGP’s assets and liabilities. As MGP holds what is deemed a majority voting interest in the Operating Partnership through its ownership of the Operating Partnership’s sole general partner, it qualifies for the exemption from providing certain of the required disclosures associated with investments in VIEs. The condensed consolidated financial statements of the Operating Partnership include the accounts of its wholly owned subsidiary, the Landlord, which owns the real estate, a VIE of which the Operating Partnership is the primary beneficiary. As of June 30, 2018, on a consolidated basis the Landlord had total assets of $9.9 billion primarily related to its real estate assets, and total liabilities of $227 million primarily related to its deferred revenue and above market lease liability.

Noncontrolling interest. The Company presents noncontrolling interest and classifies such interest as a component of consolidated shareholders’ equity, separate from the Company’s Class A shareholders’ equity. Noncontrolling interest in the Company represents Operating Partnership units currently held by subsidiaries of MGM. Net income or loss of the Operating Partnership is allocated to its noncontrolling interest based on the noncontrolling interest’s ownership percentage in the Operating Partnership except for income tax expenses. Ownership percentage is calculated by dividing the number of Operating Partnership units held by the noncontrolling interest by the total Operating Partnership units held by the noncontrolling interest and the Company. Issuance of additional Class A shares and Operating Partnership units changes the ownership interests of both the noncontrolling interest and the Company. Such transactions and the related proceeds are treated as capital transactions.

MGM may tender its Operating Partnership units for redemption by the Operating Partnership in exchange for cash equal to the market price of MGP’s Class A shares at the time of redemption or for unregistered Class A shares on a one-for-one basis. Such selection to pay cash or issue Class A shares to satisfy an Operating Partnership unitholder’s redemption request is solely within the control of MGP’s independent conflicts committee.

Real estate investments. Real estate investments consist of land, buildings, improvements and integral equipment. The contribution or acquisition of the real property by the Operating Partnership from MGM represent transactions between entities under common control, and as a result, such real estate was initially recorded by the Company at MGM’s historical cost basis, less accumulated depreciation (i.e., there was no change in the basis of the contributed assets), as of the contribution or acquisition dates. Costs of maintenance and repairs to real estate investments are the responsibility of the Tenant under the Master Lease.

Although the Tenant is responsible for all capital expenditures during the term of the Master Lease, if, in the future, a deconsolidation event occurs, the Company will be required to pay the Tenant, should the Tenant so elect, for certain capital improvements that would not constitute “normal tenant improvements” in accordance with U.S. GAAP (“Non-Normal Tenant Improvements”), subject to an initial cap of $100 million in the first year of the Master Lease increasing annually by $75 million each year thereafter. The Company will be entitled to receive additional rent based on the 10-year Treasury yield plus 600 basis points multiplied by the value of the new capital improvements the Company is required to pay for in connection with a deconsolidation event and such capital improvements will be subject to the terms of the Master Lease. Examples of Non-Normal Tenant Improvements include the costs of structural elements at the properties, including capital improvements that expand the footprint or square footage of any of the properties or extend the useful life of the properties, as well as equipment that would be a necessary improvement at any of the properties, including initial installation of elevators, air conditioning systems or electrical wiring. Such Non-Normal Tenant Improvements are capitalized and depreciated over the asset’s remaining life. Inception-to-date Non-Normal Tenant Improvements were $138.9 million through June 30, 2018.

Deferred revenue. The Company receives nonmonetary consideration related to Non-Normal Tenant Improvements as they become MGP’s property pursuant to the Master Lease, and recognizes the cost basis of Non-Normal Tenant Improvements as real estate investments and deferred revenue. The Company depreciates the real estate investments over their estimated useful lives and amortizes the deferred revenue as additional rental revenue over the remaining term of the Master Lease once the related real estate assets are placed in service.

Income tax provision. For interim income tax reporting the Company estimates its annual effective tax rate and applies it to its year-to-date ordinary income. The tax effects of unusual or infrequently occurring items, including changes in judgment about valuation allowances and effects of changes in tax laws or rates, are reported in the interim period in which they occur. The Company’s effective income tax rate was 2.6% and 2.3% for the three and six months ended June 30, 2018, respectively. The provision for current taxes and the deferred tax liability in the accompanying financial statements are attributable to noncontrolling interest since the payment of such taxes are the responsibility of MGM.

Recently issued accounting standards. In August 2017, the FASB issued Accounting Standards Update No. 2017-12, Derivatives and Hedging (Topic 815): Targeted Improvements to Accounting for Hedging Activities (“ASU 2017-12”). ASU 2017-12 is effective for fiscal years beginning after December 15, 2018, and interim periods within those years. ASU 2017-12 amends the hedge accounting recognition and presentation requirements in order to improve the transparency and understandability of information about an entity’s risk management activities, and simplifies the application of hedge accounting. The Company is currently assessing the impact that adoption of this guidance will have on its consolidated financial statements and footnote disclosures.

In 2016 and 2018, the FASB issued ASC 842 “Leases (Topic 842),” which replaces the existing guidance in ASC 840, “Leases.” ASC 842 is effective for fiscal years, and interim periods within those years, beginning after December 15, 2018. ASC 842 requires a dual approach for lessee accounting under which a lessee would account for leases as finance leases or operating leases. Both finance leases and operating leases will result in the lessee recognizing a right-of-use (“ROU”) asset and a corresponding lease liability. For finance leases, the lessee would recognize interest expense and amortization of the ROU asset and for operating leases the lessee would recognize a straight-line total lease expense. The Company is currently assessing the impact the adoption of ASC 842 will have on its consolidated financial statements and footnote disclosures.

In May 2014, the FASB issued ASC 606, Revenue from Contracts with Customers (Topic 606) which outlines a new, single comprehensive model for entities to use in accounting for revenue arising from contracts with customers and supersedes most current revenue recognition guidance, including industry-specific guidance. Under the standard, revenue is recognized when a customer obtains control of promised goods or services in an amount that reflects the consideration the entity expects to receive in exchange for those goods and services. The Company adopted ASC 606 on January 1, 2018 and it did not have a material impact on the Company’s financial statements and footnote disclosures.