SEGMENT INFORMATION - Narrative (Details) $ in Thousands	3 Months Ended	12 Months Ended
	Jun. 30, 2020 USD ($)	Dec. 31, 2020 USD ($) reportable_segment	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments | reportable_segment		3
Asset impairment charges	$ 61,109	$ 61,109	$ 64,206	$ 0
Net sales		764,041	837,398	785,897
Sales Revenue | Customer Concentration Risk | Ford Motor Company
Segment Reporting Information [Line Items]
Net sales			$ 99,100	$ 116,100
Concentration risk (as a percent)			11.80%	14.80%
Performance Materials Segment
Segment Reporting Information [Line Items]
Asset impairment charges	$ 61,109
Performance Materials Segment | Operating Segments
Segment Reporting Information [Line Items]
Asset impairment charges		61,100	$ 64,200
Net sales		$ 264,645	$ 245,480	$ 169,217