LONG-TERM DEBT - Credit Facilities (Details) (USD $)	6 Months Ended	1 Months Ended
	Mar. 31, 2015	Nov. 30, 2013	Sep. 30, 2014	Jul. 31, 2012
Debt Instrument [Line Items]
Long-term debt, excluding capital leases	1,725,969,000		$ 1,730,936,000
Accrued interest payable	9,876,000		8,659,000
Credit Facility
Debt Instrument [Line Items]
Accrued interest including commitment fees	230,000		212,000
Senior Secured Credit Facility - Term Loan A | Credit Facility
Debt Instrument [Line Items]
Debt outstanding	116,400,000
Long-term debt, excluding capital leases	115,960,000		119,789,000
Senior Secured Credit Facility - Term Loan A | Credit Facility | Eurodollar Rate Term Loans
Debt Instrument [Line Items]
Basis spread on variable rate	4.25%
Variable rate at period end	0.28%
Senior Secured Credit Facility - Term Loan B, due June 2018, net of discount of $7,306 and $8,337, respectively | Credit Facility
Debt Instrument [Line Items]
Debt outstanding	720,900,000
Long-term debt, excluding capital leases	713,569,000		716,188,000
Senior Secured Credit Facility - Term Loan B, due June 2018, net of discount of $7,306 and $8,337, respectively | Credit Facility | Eurodollar Rate Term Loans
Debt Instrument [Line Items]
Basis spread on variable rate	4.50%
Variable rate at period end	1.00%
Senior Secured Credit Facility - Revolving, due June 2018 | Credit Facility
Debt Instrument [Line Items]
Debt outstanding	50,000,000
Letters of credit issued	3,000,000
Credit facility outstanding	0
Remaining borrowing capacity	46,600,000
Long-term debt, excluding capital leases	50,000,000		37,000,000
Senior Secured Credit Facility - Revolving, due June 2018 | Credit Facility | Eurodollar Rate Revolving Loans [Member]
Debt Instrument [Line Items]
Basis spread on variable rate	4.25%
Long-term debt, excluding capital leases	41,000,000
Variable rate at period end	0.18%
Senior Secured Credit Facility - Revolving, due June 2018 | Credit Facility | Base Rate
Debt Instrument [Line Items]
Basis spread on variable rate	3.25%
Long-term debt, excluding capital leases	9,000,000
Variable rate at period end	3.25%
Line of Credit | Credit Facility
Debt Instrument [Line Items]
Long-term debt, excluding capital leases	413,000		3,041,000
Borrowing capacity		16,500,000.0
Amount outstanding	413,000
Accrued interest payable	22,000		23,000
Downs Lodging Credit Facility | Credit Facility
Debt Instrument [Line Items]
Long-term debt, excluding capital leases	45,000,000		45,000,000
Downs Lodging Credit Facility | Credit Facility | Downs Lodging, LLC
Debt Instrument [Line Items]
Loan face amount				45,000,000.0
Accrued interest payable	375,000		0
Interest rate				13.00%
Interest due monthly				10.00%
Interest due at maturity				3.00%
Exit fee				3.00%
Senior Secured Notes | Senior Secured Credit Facilities | Credit Facility
Debt Instrument [Line Items]
Loan face amount		955,000,000.0
Senior Secured Notes | Senior Secured Credit Facility - Term Loan A | Credit Facility
Debt Instrument [Line Items]
Loan face amount		125,000,000
Debt instrument, amortization of principal, percentage, year one		5.00%
Debt instrument, amortization of principal, percentage, year two		7.50%
Debt instrument, amortization of principal, percentage, year three		10.00%
Senior Secured Notes | Senior Secured Credit Facility - Term Loan A | Credit Facility | Minimum
Debt Instrument [Line Items]
Variable rate, leverage-based margin		2.50%
Senior Secured Notes | Senior Secured Credit Facility - Term Loan A | Credit Facility | Maximum
Debt Instrument [Line Items]
Variable rate, leverage-based margin		3.50%
Senior Secured Notes | Senior Secured Credit Facility - Term Loan A | Credit Facility | London Interbank Offered Rate (LIBOR) | Minimum
Debt Instrument [Line Items]
Variable rate, leverage-based margin		3.50%
Senior Secured Notes | Senior Secured Credit Facility - Term Loan A | Credit Facility | London Interbank Offered Rate (LIBOR) | Maximum
Debt Instrument [Line Items]
Variable rate, leverage-based margin		4.50%
Senior Secured Notes | Senior Secured Credit Facility - Term Loan A | Credit Facility | Federal Funds Effective Swap Rate
Debt Instrument [Line Items]
Basis spread on variable rate		0.50%
Senior Secured Notes | Senior Secured Credit Facility - Term Loan A | Credit Facility | One-Month London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Basis spread on variable rate		1.00%
Senior Secured Notes | Senior Secured Credit Facility - Term Loan B, due June 2018, net of discount of $7,306 and $8,337, respectively | Credit Facility
Debt Instrument [Line Items]
Loan face amount		730,000,000
Debt instrument, amortization of principal, percentage, annual		1.00%
Senior Secured Notes | Senior Secured Credit Facility - Term Loan B, due June 2018, net of discount of $7,306 and $8,337, respectively | Credit Facility | London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Basis spread on variable rate		4.50%
Variable rate basis, minimum		1.00%
Senior Secured Notes | Senior Secured Credit Facility - Term Loan B, due June 2018, net of discount of $7,306 and $8,337, respectively | Credit Facility | Base Rate
Debt Instrument [Line Items]
Basis spread on variable rate		3.50%
Variable rate basis, minimum		2.00%
Revolving Loans | Senior Secured Credit Facilities | Credit Facility
Debt Instrument [Line Items]
Loan face amount		100,000,000
Revolving Loans | Senior Secured Credit Facility - Term Loan B, due June 2018, net of discount of $7,306 and $8,337, respectively | Credit Facility
Debt Instrument [Line Items]
Fee assessed on unused revolving credit	0.50%
Revolving Loans | Senior Secured Credit Facility - Term Loan B, due June 2018, net of discount of $7,306 and $8,337, respectively | Credit Facility | Minimum
Debt Instrument [Line Items]
Fee assessed on unused revolving credit		0.375%
Revolving Loans | Senior Secured Credit Facility - Term Loan B, due June 2018, net of discount of $7,306 and $8,337, respectively | Credit Facility | Maximum
Debt Instrument [Line Items]
Fee assessed on unused revolving credit		0.50%
Senior Secured Credit Facility - Term Loan A | Senior Secured Credit Facilities | Credit Facility | London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Variable rate, measurement period		1 month