BASIS OF PRESENTATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Advertising Costs and Expenses & Severence Costs and Expenses (Details) (USD $)	12 Months Ended			1 Months Ended	12 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012 2012 Restructuring Plan employee	Sep. 30, 2013 2012 Restructuring Plan	Sep. 30, 2013 2012 Restructuring Plan Mohegan Sun	Sep. 30, 2013 2012 Restructuring Plan Corporate	Sep. 30, 2013 2012 Restructuring Plan Mohegan Sun at Pocono Downs
Schedule of Accrued Severance Liability By Segment [Line Items]
Advertising costs and expenses	$ 28,200,000	$ 28,200,000	$ 27,000,000
Prepaid advertising	19,000	767,000
Approximate workforce reductions (in positions)				330
Severance charges	29,000	12,521,000	244,000
Restructuring Reserve [Roll Forward]
Balance					12,521,000	12,497,000	24,000	0
Accrued severance at measurement date					124,000	0	0	124,000
Adjustments					(95,000)	(146,000)	0	51,000
Cash payments					(11,133,000)	(10,934,000)	(24,000)	(175,000)
Balance				$ 12,521,000	$ 1,417,000	$ 1,417,000	$ 0	$ 0