BASIS OF PRESENTATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Fair Value of Financial Instruments (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Sep. 30, 2015	Aug. 31, 2013	Mar. 31, 2012
Senior Unsecured Notes | 2013 9 3/4% Senior Unsecured Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate (as a percent)	9.75%	9.75%	9.75%
Senior Subordinated Notes | 2012 11 % Senior Subordinated Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate (as a percent)	11.00%	11.00%		11.00%
Fair Value, Inputs, Level 2 | Senior Unsecured Notes | 2015 Senior Unsecured Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Note value	$ 98,375
Carrying Value | Fair Value, Inputs, Level 2 | Credit Facility | Bank Credit Facility
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Credit facility value	13,000
Carrying Value | Fair Value, Inputs, Level 2 | Credit Facility | Term Loan A Facility
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Credit facility value	95,399
Carrying Value | Fair Value, Inputs, Level 2 | Credit Facility | Term Loan B Facility
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Credit facility value	765,002
Carrying Value | Fair Value, Inputs, Level 2 | Senior Unsecured Notes | 2013 9 3/4% Senior Unsecured Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Note value	578,525
Carrying Value | Fair Value, Inputs, Level 2 | Senior Unsecured Notes | 2015 Senior Unsecured Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Note value	$ 98,321
Carrying Value | Fair Value, Inputs, Level 2 | Senior Subordinated Notes | 2013 9 3/4% Senior Unsecured Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate (as a percent)	9.75%
Carrying Value | Fair Value, Inputs, Level 2 | Senior Subordinated Notes | 2012 11 % Senior Subordinated Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate (as a percent)	11.00%
Note value	$ 99,315
Fair Value | Fair Value, Inputs, Level 2 | Credit Facility | Bank Credit Facility
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Credit facility value	12,899
Fair Value | Fair Value, Inputs, Level 2 | Credit Facility | Term Loan A Facility
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Credit facility value	96,459
Fair Value | Fair Value, Inputs, Level 2 | Credit Facility | Term Loan B Facility
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Credit facility value	775,345
Fair Value | Fair Value, Inputs, Level 2 | Senior Unsecured Notes | 2013 9 3/4% Senior Unsecured Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Note value	631,069
Fair Value | Fair Value, Inputs, Level 2 | Senior Subordinated Notes | 2012 11 % Senior Subordinated Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Note value	$ 100,440