Segment Reporting (Details) - USD ($) $ in Thousands		3 Months Ended
		Apr. 30, 2017	Apr. 30, 2016
Segment Reporting Information [Line Items]
Net sales		$ 93,535	$ 68,360
Operating income		18,219	8,050
Administrative and general expenses	[1]	(5,370)	(4,338)
Applied Technology [Member]
Segment Reporting Information [Line Items]
Gain (Loss) on Disposition of Assets		161
Net sales		40,490	31,456
Operating income	[2]	13,453	8,693
Engineered Films [Member]
Segment Reporting Information [Line Items]
Net sales		43,555	29,100
Operating income	[2]	8,720	3,878
Aerostar [Member]
Segment Reporting Information [Line Items]
Gain (Loss) on Disposition of Assets			(70)
Net sales		9,606	7,895
Operating income	[2]	1,418	(178)
Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Net sales	[3]	(116)	(91)
Operating income	[3]	(2)	(5)
Corporate Segment [Member]
Segment Reporting Information [Line Items]
Operating income		$ 23,589	$ 12,388

[1] (c) At the segment level, operating income does not include an allocation of general and administrative expenses and, as a result, "General and administrative expenses" are reported as a deduction from "Total reportable segment income" to reconcile to "Operating income" reported in the Consolidated Statements of Income and Comprehensive Income.

[2] (b) At the segment level, operating income does not include an allocation of general and administrative expenses.

[3] (a) Intersegment sales for both fiscal 2018 and 2017 were primarily sales from Engineered Films to Aerostar.