SUBSEQUENT EVENTS	6 Months Ended
Mar. 31, 2017
Subsequent Events [Abstract]
SUBSEQUENT EVENTS	SUBSEQUENT EVENTS: Amendment to Senior Secured Credit Facilities On April 14, 2017, the Authority entered into a First Amendment to Credit Agreement by and among the Authority, the Tribe, Citizens Bank, N.A., as Administrative and Collateral Agent, and the other lenders and financial institutions party thereto, amending the Authority’s Senior Secured Credit Facilities. The amendment reduces the interest rate margins applicable to the Revolving Facility, Term Loan A Facility and Term Loan B Facility by 0.50%. The Authority incurred approximately $3.0 million in transaction costs in connection with this amendment. The Authority has not yet completed its evaluation of the accounting of these transaction costs. Mohegan Sun Exposition and Convention Center In March 2017, the Authority commenced its $80.0 million exposition and convention center expansion project at Mohegan Sun. The approximately 240,000-square-foot exposition and convention center is anticipated to include a convention and conference center, a ballroom, 18 meeting rooms, a boardroom with an outdoor terrace and a kitchen. The exposition and convention center, which will be located adjacent to and fully integrated into Mohegan Sun, is being developed and built by Mohegan Expo, a wholly-owned subsidiary of the Authority, on an approximately 4.6-acre parcel of land leased from the Authority. The costs for the exposition and convention center are being funded through a combination of third-party financing obtained by Mohegan Expo of up to approximately $33.0 million and an investment by the Authority. The Authority incurred approximately $1.5 million in transaction costs in connection with the third-party financing. The Authority has not yet completed its evaluation of the accounting of these transaction costs. The exposition and convention center is expected to open in the summer of 2018. Cowlitz Project Membership Interest Redemption and Withdrawal Agreement On April 14, 2017, Salishan Company and Salishan-Mohegan entered into a Membership Interest Redemption and Withdrawal Agreement (the “Redemption and Withdrawal Agreement”), pursuant to which Salishan-Mohegan agreed to redeem all of Salishan Company’s right, title and interest in and to its membership interests of Salishan-Mohegan, and Salishan Company agreed to resign and irrevocably withdraw as a member of Salishan-Mohegan. As a result of this withdrawal, Mohegan Ventures-NW and a subsidiary of the Tribe now hold membership interests in Salishan-Mohegan of 81.92% and 18.08%, respectively. As consideration for the redemption, Salishan-Mohegan agreed to pay Salishan Company a redemption price, the amount of which will be determined by future binding arbitration. In connection with the Redemption and Withdrawal Agreement, the parties also formed a new joint venture development entity, Salishan-Mohegan Development Company, LLC (“SMDC”), to which Salishan-Mohegan has assigned a right of first refusal for certain subsequent material expansion or future development as provided in the development agreement for the Cowlitz Project. Mohegan Ventures-NW, Salishan Company and a subsidiary of the Tribe hold membership interests in SMDC of 49.15%, 40% and 10.85%, respectively.

SUBSEQUENT EVENTS:

Amendment to Senior Secured Credit Facilities

On April 14, 2017, the Authority entered into a First Amendment to Credit Agreement by and among the Authority, the Tribe, Citizens Bank, N.A., as Administrative and Collateral Agent, and the other lenders and financial institutions party thereto, amending the Authority’s Senior Secured Credit Facilities. The amendment reduces the interest rate margins applicable to the Revolving Facility, Term Loan A Facility and Term Loan B Facility by 0.50%. The Authority incurred approximately $3.0 million in transaction costs in connection with this amendment. The Authority has not yet completed its evaluation of the accounting of these transaction costs.

Mohegan Sun Exposition and Convention Center

In March 2017, the Authority commenced its $80.0 million exposition and convention center expansion project at Mohegan Sun. The approximately 240,000-square-foot exposition and convention center is anticipated to include a convention and conference center, a ballroom, 18 meeting rooms, a boardroom with an outdoor terrace and a kitchen. The exposition and convention center, which will be located adjacent to and fully integrated into Mohegan Sun, is being developed and built by Mohegan Expo, a wholly-owned subsidiary of the Authority, on an approximately 4.6-acre parcel of land leased from the Authority. The costs for the exposition and convention center are being funded through a combination of third-party financing obtained by Mohegan Expo of up to approximately $33.0 million and an investment by the Authority. The Authority incurred approximately $1.5 million in transaction costs in connection with the third-party financing. The Authority has not yet completed its evaluation of the accounting of these transaction costs. The exposition and convention center is expected to open in the summer of 2018.

Cowlitz Project Membership Interest Redemption and Withdrawal Agreement

On April 14, 2017, Salishan Company and Salishan-Mohegan entered into a Membership Interest Redemption and Withdrawal Agreement (the “Redemption and Withdrawal Agreement”), pursuant to which Salishan-Mohegan agreed to redeem all of Salishan Company’s right, title and interest in and to its membership interests of Salishan-Mohegan, and Salishan Company agreed to resign and irrevocably withdraw as a member of Salishan-Mohegan. As a result of this withdrawal, Mohegan Ventures-NW and a subsidiary of the Tribe now hold membership interests in Salishan-Mohegan of 81.92% and 18.08%, respectively. As consideration for the redemption, Salishan-Mohegan agreed to pay Salishan Company a redemption price, the amount of which will be determined by future binding arbitration. In connection with the Redemption and Withdrawal Agreement, the parties also formed a new joint venture development entity, Salishan-Mohegan Development Company, LLC (“SMDC”), to which Salishan-Mohegan has assigned a right of first refusal for certain subsequent material expansion or future development as provided in the development agreement for the Cowlitz Project. Mohegan Ventures-NW, Salishan Company and a subsidiary of the Tribe hold membership interests in SMDC of 49.15%, 40% and 10.85%, respectively.