SEGMENT INFORMATION - Business Segment Net Sales (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Segment Reporting Information [Line Items]
Net sales	$ 643,705	$ 643,679	$ 594,790
HNH | Operating Segments
Segment Reporting Information [Line Items]
Net sales	347,433	341,237	315,796
ANH | Operating Segments
Segment Reporting Information [Line Items]
Net sales	177,557	175,693	157,688
Specialty Products | Operating Segments
Segment Reporting Information [Line Items]
Net sales	92,257	75,808	73,355
Industrial Products | Operating Segments
Segment Reporting Information [Line Items]
Net sales	$ 26,458	$ 50,941	$ 47,951