BUSINESS DESCRIPTION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	May 28, 2019
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net sales	$ 180,713	$ 175,140	$ 173,355	$ 174,436	$ 166,527	$ 158,595	$ 161,554	$ 157,029	$ 703,644	$ 643,705	$ 643,679
Goodwill impairment - see Note 6									1,228
Goodwill	529,463				523,998				529,463	523,998	447,995
Currency swap | Designated as Hedging Instrument
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Notional amount of derivatives												$ 108,569
Interest rate swap | Designated as Hedging Instrument
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Notional amount of derivatives												$ 108,569
HNH
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Goodwill	$ 424,051				$ 423,600				$ 424,051	423,600
Impairment charges										$ 1,026
Difference between Revenue Guidance in Effect before and after Topic 606
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net sales											$ 338