FAIR VALUE MEASUREMENTS AND DERIVATIVES - Summary of Carrying Amounts and Estimated Fair Values of the Company's Long-term Debt (Details) - USD ($) $ in Thousands		Sep. 30, 2021	Dec. 31, 2020
Carrying Value [Member]
Debt Instrument [Line Items]
Total debt	[1]	$ 234,457	$ 234,457
Carrying Value [Member] | First Lien Revolving Facility [Member]
Debt Instrument [Line Items]
Total debt		7,000	7,000
Estimated Fair Value [Member]
Debt Instrument [Line Items]
Total debt	[1]	232,350	216,190
Estimated Fair Value [Member] | First Lien Revolving Facility [Member]
Debt Instrument [Line Items]
Total debt		6,930	6,680
First Lien Term Loan Facility [Member] | Carrying Value [Member]
Debt Instrument [Line Items]
Total debt		202,457	202,457
First Lien Term Loan Facility [Member] | Estimated Fair Value [Member]
Debt Instrument [Line Items]
Total debt		200,930	188,560
Second Lien Term Loan Facility [Member] | Carrying Value [Member]
Debt Instrument [Line Items]
Total debt		25,000	25,000
Second Lien Term Loan Facility [Member] | Estimated Fair Value [Member]
Debt Instrument [Line Items]
Total debt		$ 24,490	$ 20,950

[1] The debt amounts above do not include the impact of the interest rate swap or debt issuance costs.