Segment Reporting (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jul. 31, 2021	Jul. 31, 2020	Jul. 31, 2021	Jul. 31, 2020
Segment Reporting Information [Line Items]
Net sales	$ 114,426	$ 85,179	$ 226,912	$ 171,675
Operating income	8,334	6,143	19,907	10,082
Applied Technology [Member]
Segment Reporting Information [Line Items]
Net sales	44,601	35,502	99,469	77,509
Operating income	8,505	6,511	21,692	15,450
Engineered Films [Member]
Segment Reporting Information [Line Items]
Net sales	57,087	36,252	105,852	69,650
Operating income	12,357	4,465	19,124	6,072
Aerostar [Member]
Segment Reporting Information [Line Items]
Net sales	12,787	13,465	21,674	24,616
Operating income	1,962	1,751	2,551	2,044
Eliminations [Member]
Segment Reporting Information [Line Items]
Net sales	(49)	(40)	(83)	(100)
Operating income	5	11	(2)	51
Reportable Segments
Segment Reporting Information [Line Items]
Net sales	114,426	85,179	226,912	171,675
Operating income	22,829	12,738	43,365	23,617
Corporate Segment [Member]
Segment Reporting Information [Line Items]
Administrative and general expenses	$ (14,495)	$ (6,595)	$ (23,458)	$ (13,535)