BASIS OF PRESENTATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Fair Value of Financial Instruments (Details) - Fair value, inputs, level 2 $ in Thousands	Sep. 30, 2018 USD ($)
Carrying Value | Credit facility | Senior Secured Credit Facility - Revolving
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Credit facility value	$ 66,000
Carrying Value | Credit facility | Senior Secured Credit Facility - Term Loan A
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Credit facility value	311,466
Carrying Value | Credit facility | Senior Secured Credit Facility - Term Loan B
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Credit facility value	810,430
Carrying Value | 2016 7 7/8% Senior Unsecured Notes | 2016 7 7/8% Senior Unsecured Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Note value	$ 488,967
Note stated interest rate	7.875%
Fair Value | Credit facility | Senior Secured Credit Facility - Revolving
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Credit facility value	$ 64,503
Fair Value | Credit facility | Senior Secured Credit Facility - Term Loan A
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Credit facility value	311,924
Fair Value | Credit facility | Senior Secured Credit Facility - Term Loan B
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Credit facility value	782,329
Fair Value | 2016 7 7/8% Senior Unsecured Notes | 2016 7 7/8% Senior Unsecured Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Note value	$ 493,150