Segment Reporting (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jul. 31, 2015	Jul. 31, 2014	Jul. 31, 2015	Jul. 31, 2014
Segment Reporting Information [Line Items]
Net sales		$ 67,518	$ 94,485	$ 137,791	$ 196,995
Operating income		6,429	10,696	13,643	27,228
Administrative and general expenses		(4,316)	(5,495)	(9,520)	(10,755)
Gain (Loss) on Disposition of Assets		(247)		(611)
Applied Technology Division [Member]
Segment Reporting Information [Line Items]
Net sales		20,411	36,247	52,821	82,535
Operating income	[1]	4,041	8,829	12,782	24,685
Gain (Loss) on Disposition of Assets		(247)		(611)
Engineered Films [Member]
Segment Reporting Information [Line Items]
Net sales		35,789	42,299	67,110	84,506
Operating income		5,365	5,816	9,836	11,679
Aerostar Division [Member]
Segment Reporting Information [Line Items]
Net sales		11,328	19,257	17,882	36,922
Operating income	[2]	1,314	1,628	461	1,639
Gain (Loss) on Disposition of Assets		70		70
Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Net sales	[3]	(10)	(3,318)	(22)	(6,968)
Operating income	[3]	25	(82)	84	(20)
Corporate Segment [Member]
Segment Reporting Information [Line Items]
Operating income		$ 10,745	$ 16,191	$ 23,163	$ 37,983

[1] (b) Includes gains of $247 and $611 for the three- and six-month periods ended July 31, 2015, respectively, on disposal of assets related to the exit of contract manufacturing operations.

[2] (c) Includes $(70) loss for both the three- and six-month periods ended July 31, 2015 on disposal of an idle manufacturing plant held for sale.

[3] (a) Fiscal 2016 intersegment sales were primarily sales from Engineered Films to Aerostar. Fiscal 2015 intersegment sales were comprised primarily of contract manufacturing sales from Aerostar to Applied Technology.