Goodwil, Long-lived Assets, and Other Charges - Changes in the Carrying Amount of Goodwill by Reporting Segment (Details) - USD ($) $ in Thousands	12 Months Ended
	Jan. 31, 2019	Jan. 31, 2018
Goodwill [Roll Forward]
Goodwill, beginning balance	$ 46,710	$ 40,649
Goodwill, Acquired During Period	4,559	5,714
Goodwill, Written off Related to Sale of Business Unit	(103)	(52)
Goodwill, Foreign Currency Translation Gain (Loss)	(224)	399
Goodwill, end balance	50,942	46,710
Applied Technology
Goodwill [Roll Forward]
Goodwill, beginning balance	12,741	12,342
Goodwill, Acquired During Period	4,559	0
Goodwill, Written off Related to Sale of Business Unit	0	0
Goodwill, Foreign Currency Translation Gain (Loss)	(224)	399
Goodwill, end balance	17,076	12,741
Engineered Films
Goodwill [Roll Forward]
Goodwill, beginning balance	33,232	27,518
Goodwill, Acquired During Period	0	5,714
Goodwill, Written off Related to Sale of Business Unit	0	0
Goodwill, Foreign Currency Translation Gain (Loss)	0	0
Goodwill, end balance	33,232	33,232
Aerostar
Goodwill [Roll Forward]
Goodwill, beginning balance	737	789
Goodwill, Acquired During Period	0	0
Goodwill, Written off Related to Sale of Business Unit	(103)	(52)
Goodwill, Foreign Currency Translation Gain (Loss)	0	0
Goodwill, end balance	$ 634	$ 737