FAIR VALUE OF FINANCIAL INSTRUMENTS (Details) (USD $)	Sep. 30, 2012	Sep. 30, 2011
Fair Value Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long term debt, carrying amount	$ 830,000,000	$ 520,000,000
Senior Notes [Member]
Fair Value Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long term debt, carrying amount	450,000,000
Long-term debt, fair value	478,000,000
Level 2 [Member] | Interest Rate Swap [Member] | Maximum [Member]
Fair Value Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Credit adjustment to total fair value percentage	3.00%
Fair Value, Measurements, Recurring [Member] | Carrying Amount [Member] | Interest Rate Swap [Member]
Fair Value Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total derivative contracts, net	3,119,000	1,619,000
Fair Value, Measurements, Recurring [Member] | Carrying Amount [Member] | Interest Rate Swap [Member] | Accrued liabilities [Member]
Fair Value Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total derivative contracts, net	1,705,000	988,000
Fair Value, Measurements, Recurring [Member] | Carrying Amount [Member] | Interest Rate Swap [Member] | Other long-term liabilities [Member]
Fair Value Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total derivative contracts, net	1,414,000	631,000
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Interest Rate Swap [Member]
Fair Value Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total derivative contracts, net	0	0
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Interest Rate Swap [Member] | Accrued liabilities [Member]
Fair Value Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total derivative contracts, net	0	0
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Interest Rate Swap [Member] | Other long-term liabilities [Member]
Fair Value Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total derivative contracts, net	0	0
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Interest Rate Swap [Member]
Fair Value Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total derivative contracts, net	3,119,000	1,619,000
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Interest Rate Swap [Member] | Accrued liabilities [Member]
Fair Value Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total derivative contracts, net	1,705,000	988,000
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Interest Rate Swap [Member] | Other long-term liabilities [Member]
Fair Value Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total derivative contracts, net	1,414,000	631,000
Fair Value, Measurements, Recurring [Member] | Level 3 [Member] | Interest Rate Swap [Member]
Fair Value Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total derivative contracts, net	0	0
Fair Value, Measurements, Recurring [Member] | Level 3 [Member] | Interest Rate Swap [Member] | Accrued liabilities [Member]
Fair Value Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total derivative contracts, net	0	0
Fair Value, Measurements, Recurring [Member] | Level 3 [Member] | Interest Rate Swap [Member] | Other long-term liabilities [Member]
Fair Value Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total derivative contracts, net	0	0
Fair Value, Measurements, Recurring [Member] | Estimated Fair Value [Member] | Interest Rate Swap [Member]
Fair Value Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total derivative contracts, net	3,119,000	1,619,000
Fair Value, Measurements, Recurring [Member] | Estimated Fair Value [Member] | Interest Rate Swap [Member] | Accrued liabilities [Member]
Fair Value Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total derivative contracts, net	1,705,000	988,000
Fair Value, Measurements, Recurring [Member] | Estimated Fair Value [Member] | Interest Rate Swap [Member] | Other long-term liabilities [Member]
Fair Value Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total derivative contracts, net	$ 1,414,000	$ 631,000