LONG-TERM DEBT (Details Textual) - USD ($)		1 Months Ended				3 Months Ended					12 Months Ended
	Feb. 10, 2014	Dec. 19, 2018	Apr. 18, 2017	Apr. 21, 2016	Apr. 17, 2015	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2018	Dec. 31, 2017	Dec. 20, 2018
Debt Instrument [Line Items]
Covenant Compliance Description For Maintaining Interest Coverage Ratio												maintaining an interest coverage ratio of no less than:$1.25 to 1.00 on June 30, 2017 and the last day of each fiscal quarter thereafter
Covenant Compliance Description For Maintaining Total Leverage Ratio												maintaining a senior leverage ratio of no greater than: $5.85 to 1.00 on June 30, 2017 and the last day of each fiscal quarter thereafter.
Letters of Credit Outstanding, Amount						$ 788,000
Long-term Debt, Gross						0	$ 350,000,000				$ 350,000,000
Debt Instrument, Interest Rate, Stated Percentage							9.25%				9.25%
Gain Losses on Extinguishment of Debt						0				$ 239,000
Debt Instrument, Interest Rate Terms			The 2017 Credit Facility contains customary representations and warranties and events of default, affirmative and negative covenants (in each case, subject to materiality exceptions and qualifications) which may be more restrictive than those governing the Notes. The 2017 Credit Facility also contains certain financial covenants, including a maintenance covenant requiring the Company’s interest expense coverage ratio (defined as the ratio of consolidated EBITDA to consolidated interest expense) to be greater than or equal to 1.25 to 1.00 and its total senior secured leverage ratio (defined as the ratio of consolidated net senior secured indebtedness to consolidated EBITDA) to be less than or equal to 5.85 to 1.00.								The 2018 Credit Facility contains customary representations and warranties and events of default, affirmative and negative covenants (in each case, subject to materiality exceptions and qualifications). The 2018 Credit Facility also contains certain financial covenants, including a maintenance covenant requiring the Company's total gross leverage ratio to be not greater than 8.0 to 1.00 in 2019, 7.5 to 1.00 in 2020, 7.25 to 1.00 in 2021 and 6.75 to 1.00 in 2022.
Interest Expense, Total						22,151,000				19,281,000
Debt Instrument Additional Interest Payment Term On Prepayment			Beginning with the interest payment date occurring in June 2017 and ending in March 2023, the Company will be required to repay principal, to the extent then outstanding, equal to 1∕4 of 1% of the aggregate initial principal amount of all term loans incurred on the effective date of the 2017 Credit Facility.
Comcast Note [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount						$ 11,900,000
Long-term Debt, Gross							$ 11,900,000				$ 11,900,000
Debt Instrument, Interest Rate, Stated Percentage						10.47%
2022 Notes
Debt Instrument [Line Items]
Long-term Debt, Gross					$ 350,000,000
Debt Instrument, Description					an original issue price of 100.0% plus accrued interest
9.25% Senior Subordinated Notes due February 2020 [Member]
Debt Instrument [Line Items]
Long-term Debt, Gross							2,000,000				2,000,000
Debt Instrument, Interest Rate, Stated Percentage						9.25%
Gain Losses on Extinguishment of Debt							2,800,000
Debt Instrument, Repurchase Amount							$ 243,000,000				$ 243,000,000
Debt Instrument, Redemption Price, Percentage							100.88%
Write off of Deferred Debt Issuance Cost							$ 649,000
Premium Paid to the Bondholders							2,100,000
9.25% Senior Subordinated Notes due February 2020 [Member] | Private Offering [Member]
Debt Instrument [Line Items]
Long-term Debt, Gross	$ 335,000,000
Debt Instrument, Periodic Payment	$ 15,500,000
7.375% Senior Subordinated Notes due April 2022 [Member]
Debt Instrument [Line Items]
Debt Instrument, Description					The 2022 Notes were offered at an original issue price of 100.0% plus accrued interest from April 17, 2015, and will mature on April 15, 2022. Interest on the 2022
MGM National Harbor Loan [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount						$ 50,000,000
Long-term Debt, Gross						50,500,000
Debt Instrument, Unamortized Discount (Premium), Net						1,000,000
Long Term Debt Percentage Paid In Kind											4.00%
Debt Issuance Costs, Net						1,700,000
Asset Backed Credit Facility [Member]
Debt Instrument [Line Items]
Long-term Debt, Gross						3,000,000
Line of Credit Facility, Maximum Borrowing Capacity				$ 25,000,000
Percentage Borrowing Of Eligible Accounts				(85.00%)
2017 Credit Facility [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount			$ 350,000,000
Repayments of Long-term Debt, Total		$ 20,000,000				824,000				875,000
Long-term Debt, Gross			$ 350,000,000			323,100,000	323,900,000				$ 323,900,000
Debt Instrument, Description			The 2017 Credit Facility matures on the earlier of (i) April 18, 2023, or (ii) in the event such debt is not repaid or refinanced, 91 days prior to the maturity of either of the Company’s 2022 Notes or the Company’s 2020 Notes. At the Company’s election, the interest rate on borrowings under the 2017 Credit Facility are based on either (i) the then applicable base rate (as defined in the 2017 Credit Facility) as, for any day, a rate per annum (rounded upward, if necessary, to the next 1/100th of 1%) equal to the greater of (a) the prime rate published in the Wall Street Journal, (b) 1/2 of 1% in excess rate of the overnight Federal Funds Rate at any given time, (c) the one-month LIBOR rate commencing on such day plus 1.00%) and (d) 2%, or (ii) the then applicable LIBOR rate (as defined in the 2017 Credit Facility). The average interest rate was approximately 6.51% for 2019 and was 5.71% for 2018.
2018 Credit Facility [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount													$ 192,000,000
Repayments of Long-term Debt, Total						10,600,000
Long-term Debt, Gross						181,400,000	$ 192,000,000				$ 192,000,000
Debt Instrument, Description											The 2018 Credit Facility matures on December 31, 2022 (the "Maturity Date"). Interest rates on borrowings under the 2018 Credit Facility will be either (i) from the Funding Date to the Maturity Date, 12.875% per annum, (ii) 11.875% per annum, once 50% of the term loan borrowings have been repaid or (iii) 10.875% per annum, once 75% of the term loan borrowings have been repaid. Interest payments begin on the last day of the 3-month period commencing on the Funding Date.
Interest Expense, Total						943,000				715,000
Debt Instrument Additional Interest Payment Term On Prepayment											The term loans may be voluntarily prepaid prior to February 15, 2020 subject to payment of a prepayment premium. The Company will be required to repay principal to the extent then outstanding on each quarterly interest payment date, commencing on the quarterly interest payment date ending March 2019, equal to one quarter of 7.5% of the aggregate initial principal amount of all term loans incurred on the Funding Date to December 2019, commencing on the quarterly interest payment date ending March 2020, one quarter of 10.0% of the aggregate initial principal amount of all term loans incurred on the Funding Date to December 2021, and, commencing on the quarterly interest payment date ending March 2021, one quarter of 12.5% of the aggregate initial principal amount of all term loans incurred on the Funding Date to December 2022. The Company will also be required to use 75% of excess cash flow (as defined in the 2018 Credit Facility, which exclude any distributions to the Company or its restricted subsidiaries in respect of its interests in the MGM National Harbor) to repay outstanding term loans at par, paid semiannually and to use 100% of all distributions to the Company or its restricted subsidiaries received in respect of its interest in the MGM National Harbor to repay outstanding terms loans at par.
Debt Instrument, Unamortized Discount (Premium), Net						3,800,000
2018 Credit Facility [Member] | Debt Financing Cost [Member]
Debt Instrument [Line Items]
Debt Issuance Costs, Net						$ 875,000
Senior Subordinated Notes Due From 2020 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage					7.375%
Gain Losses on Extinguishment of Debt								$ 120,000	$ 626,000	$ 239,000
Debt Instrument, Repurchase Amount								$ 5,000,000	$ 14,000,000			$ 11,000,000
Debt Instrument, Redemption Price, Percentage								97.25%	95.125%	97.375%