FAIR VALUE OF FINANCIAL INSTRUMENTS - Carrying Value (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Term Loan B | Carrying Value
Fair Value Of Instruments [Line Items]
Debt	$ 754,006	$ 770,000
Term Loan B | Fair Value
Fair Value Of Instruments [Line Items]
Debt	737,041	774,813
Revolver | Carrying Value
Fair Value Of Instruments [Line Items]
Debt	114,727	117,000
Revolver | Fair Value
Fair Value Of Instruments [Line Items]
Debt	114,727	117,000
Senior Notes | Carrying Value
Fair Value Of Instruments [Line Items]
Debt	400,000	400,000
Senior Notes | Fair Value
Fair Value Of Instruments [Line Items]
Debt	398,000	423,250
Notes | Carrying Value
Fair Value Of Instruments [Line Items]
Debt	425,000	425,000
Notes | Fair Value
Fair Value Of Instruments [Line Items]
Debt	429,250	454,750
Other Debt | Carrying Value
Fair Value Of Instruments [Line Items]
Debt	808	873
Letter of Credit | Carrying Value
Fair Value Of Instruments [Line Items]
Debt	$ 6,229	$ 5,862