COMMITMENTS AND CONTINGENCIES (Details) (USD $)	0 Months Ended	3 Months Ended		9 Months Ended
	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012	Sep. 30, 2012
Slot Win Contributions
Commitments and Contingencies [Line Items]
Contribution frequency period		12 months
Contribution determination criteria 1, percent of gross revenues from slot machines, lesser of				30.00%
Contribution determination criteria 2a, lesser of, percent of gross revenues from slot machines, greater of				25.00%
Contribution determination criteria 2b, lesser of, set cash contribution				$ 80,000,000.0
Contribution rate applied to excess free promotional play revenues in excess of limitation, if other than standard rate				25.00%
Limitation of excluded free promotional play as a percent of gross revenues from slot machines	5.50%			11.00%
Slot win contributions		40,200,000	43,600,000	115,100,000	130,400,000
Slot win contributions outstanding		13,300,000		13,300,000		13,700,000
Pennsylvania Slot Machine Tax
Commitments and Contingencies [Line Items]
Tax rate applied to percent of gross revenues from slot machines				55.00%
Portion of taxed revenues subject to minimum annual local share assessment				2.00%
Minimum annual local share assessment				10,000,000
Escrow deposit for tax payments		1,500,000		1,500,000
Slot machine tax expense recognized		31,800,000	33,500,000	93,000,000	100,800,000
Slot machine tax expense, outstanding		4,200,000		4,200,000		5,500,000
Pennsylvania Slot Machine Tax | Downs Racing, L.P.
Commitments and Contingencies [Line Items]
Number of slot machines at Mohegan Sun at Pocono Downs permitted by license				3,000
Permitted slot machine capacity (in slot machines)				5,000
Pennsylvania Table Game Tax
Commitments and Contingencies [Line Items]
Initial tax rate				14.00%
Additional local tax				2.00%
Initial taxation period		2 years
Subsequent table game tax rate				12.00%
Table game tax expense recognized		1,600,000	1,600,000	4,500,000	5,200,000
Table game tax expense outstanding		144,000		144,000		92,000
Pennsylvania Regulatory Fee
Commitments and Contingencies [Line Items]
Fee rate, percent of gross revenues from slot machines and table games				1.50%
Regulatory fee recognized		400,000	1,200,000	2,900,000	3,800,000
Regulatory fee outstanding		55,000		55,000		129,000
Pennsylvania Gaming Control Board Loans
Commitments and Contingencies [Line Items]
Loans granted by PGCB				36,100,000
Additional Loans granted by PGCB				63,800,000
Number of authorized gaming facilities				14
Number of authorized gaming facilities that have commenced operations				12
PGCB loan repayment period		10 years
PGCB loan repayment expense		160,000	166,000	484,000	504,000
Horsemen's Agreement
Commitments and Contingencies [Line Items]
Purses earned by horsemen and other fees outstanding		4,100,000		4,100,000		9,300,000
Priority Distribution Agreement
Commitments and Contingencies [Line Items]
Annual limit of priority distribution payments				14,000,000
Priority distribution payments		$ 4,800,000	$ 4,700,000	$ 14,400,000	$ 14,000,000