Goodwill & Other Intangibles - Changes in the carrying amount of goodwill by reporting segment (Details) $ in Thousands		12 Months Ended
		Jan. 31, 2016 USD ($) ReportingUnits	Jan. 31, 2015 USD ($)	Jan. 31, 2014 USD ($)	Oct. 31, 2015 USD ($)	Jul. 31, 2015 USD ($)
Goodwill [Line Items]
Number of reporting units in Aerostar Segment | ReportingUnits		2
Goodwill [Roll Forward]
Goodwill, beginning balance		$ 52,148	$ 22,274	$ 22,274
Acquired goodwill			30,466
Foreign currency translation adjustment		(116)	(592)
Purchase price adjustment to acquired goodwill	[1]	206
Goodwill disposed from sale of business		(69)
Goodwill, Impairment Loss		7,413	0	0
Goodwill, end balance		44,756	52,148	22,274
Goodwill, Impaired, Accumulated Impairment Loss [Abstract]
Goodwill gross of accumulated impairment losses		52,169	52,148	22,274
Applied Technology [Member]
Goodwill [Roll Forward]
Goodwill, beginning balance		12,550	9,892	9,892
Acquired goodwill			3,250
Foreign currency translation adjustment		(116)	(592)
Purchase price adjustment to acquired goodwill		0
Goodwill disposed from sale of business		(69)
Goodwill, Impairment Loss		0
Goodwill, end balance		12,365	12,550	9,892
Engineered Films [Member]
Goodwill [Roll Forward]
Goodwill, beginning balance		27,312	96	96
Acquired goodwill			27,216
Foreign currency translation adjustment		0	0
Purchase price adjustment to acquired goodwill	[1]	206
Goodwill disposed from sale of business		0
Goodwill, Impairment Loss		0
Goodwill, end balance		27,518	27,312	96
Amount of estimated fair value that exceeded the net book value						$ 50,000
Aerostar [Member]
Goodwill [Roll Forward]
Goodwill, beginning balance		789	789	789
Acquired goodwill			0
Foreign currency translation adjustment		0	0
Purchase price adjustment to acquired goodwill		0
Goodwill disposed from sale of business		0
Goodwill, Impairment Loss		0
Goodwill, end balance		789	789	789
Vista [Member]
Goodwill [Roll Forward]
Goodwill, beginning balance		11,497	11,497	11,497
Acquired goodwill			0
Foreign currency translation adjustment		0	0
Purchase price adjustment to acquired goodwill		0
Goodwill disposed from sale of business		0
Goodwill, Impairment Loss		7,413
Goodwill, end balance		$ 4,084	$ 11,497	$ 11,497
Reporting Unit, Carrying Amount in Excess of Fair Value					$ 8,000
Implied fair value amount less than carrying value recorded for the reporting unit					$ 7,413

[1] Working capital adjustment and final deferred tax adjustment for Integra acquisition (see Note 5 Acquisitions Of And Investments In Businesses And Technologies).