Goodwill & Other Intangibles Changes in the carrying amount of goodwill by reporting segment (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Jan. 31, 2013	Jan. 31, 2012	Jan. 31, 2011
Goodwill [Roll Forward]
Goodwill, beginning balance	$ 22,274	$ 10,777	$ 10,699
Acquisition earn-outs			78
Acquired goodwill	0	11,497
Goodwill, end balance	22,274	22,274	10,777
Applied Technology [Member]
Goodwill [Roll Forward]
Goodwill, beginning balance	9,892	9,892	9,814
Acquisition earn-outs			78
Acquired goodwill	0	0
Goodwill, end balance	9,892	9,892	9,892
Engineered Films [Member]
Goodwill [Roll Forward]
Goodwill, beginning balance	96	96	96
Acquisition earn-outs			0
Acquired goodwill	0	0
Goodwill, end balance	96	96	96
Aerostar [Member]
Goodwill [Roll Forward]
Goodwill, beginning balance	12,286	789	789
Acquisition earn-outs			0
Acquired goodwill	0	11,497
Goodwill, end balance	$ 12,286	$ 12,286	$ 789