Business Segments and Major Customer Information - Segment reporting information (Details) - USD ($) $ in Thousands		12 Months Ended
		Jan. 31, 2016	Jan. 31, 2015	Jan. 31, 2014
Segment Reporting Information [Line Items]
Sales		$ 258,229	$ 378,153	$ 394,677
Operating income		11,092	43,801	63,994
Assets		306,610	362,873	301,819
Capital expenditures		13,046	17,041	30,701
Depreciation and amortization		17,609	17,369	14,195
Pre-contract deferred costs written off			0	0
Goodwill impairment loss		7,413	0	0
Applied Technology [Member]
Segment Reporting Information [Line Items]
Goodwill impairment loss		0
Engineered Films [Member]
Segment Reporting Information [Line Items]
Goodwill impairment loss		0
Corporate & Other [Member]
Segment Reporting Information [Line Items]
Operating income		(17,110)	(21,704)	(18,865)
Assets	[1],[2]	66,079	74,960	74,116
Capital expenditures		661	2,523	7,189
Depreciation and amortization		1,676	2,230	1,439
Aerostar [Member]
Segment Reporting Information [Line Items]
Goodwill impairment loss		0
Vista Reporting Unit [Member]
Segment Reporting Information [Line Items]
Goodwill impairment loss		7,413
Operating Segments [Member]
Segment Reporting Information [Line Items]
Sales		258,229	378,153	394,677
Operating income		28,202	65,505	82,859
Assets		240,531	287,913	227,703
Capital expenditures		12,385	14,518	23,512
Depreciation and amortization		15,933	15,139	12,756
Operating Segments [Member] | Applied Technology [Member]
Segment Reporting Information [Line Items]
Sales		92,599	142,154	170,461
Operating income	[3]	18,319	34,557	57,000
Assets	[2]	65,490	88,764	93,395
Capital expenditures		664	3,478	9,324
Depreciation and amortization		4,428	5,569	4,332
Gain on disposal of assets		611
Operating Segments [Member] | Engineered Films [Member]
Segment Reporting Information [Line Items]
Sales		129,465	166,634	147,620
Operating income		17,892	21,802	18,154
Assets	[2]	134,942	140,023	71,602
Capital expenditures		10,780	8,241	6,681
Depreciation and amortization		7,735	6,096	5,808
Operating Segments [Member] | Aerostar [Member]
Segment Reporting Information [Line Items]
Sales		36,368	80,772	90,605
Operating income	[4]	(8,100)	8,983	7,816
Assets	[2]	40,156	59,274	63,017
Capital expenditures		941	2,799	7,507
Depreciation and amortization		3,770	3,474	2,616
Operating Segments [Member] | Vista Reporting Unit [Member]
Segment Reporting Information [Line Items]
Pre-contract deferred costs written off		2,933
Goodwill impairment loss		7,413
Reduction in fair value of contingent consideration liability		1,483
Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Operating income		91	163	(111)
Assets		(57)	(148)	(311)
Intersegment Eliminations [Member] | Applied Technology [Member]
Segment Reporting Information [Line Items]
Sales		(8)	(231)	(386)
Intersegment Eliminations [Member] | Engineered Films [Member]
Segment Reporting Information [Line Items]
Sales		(195)	(652)	(505)
Intersegment Eliminations [Member] | Aerostar [Member]
Segment Reporting Information [Line Items]
Sales		$ 0	$ (10,524)	$ (13,118)

[1] Assets are principally cash, investments, deferred taxes, and other receivables.

[2] Certain facilities owned by the Company are shared by more than one reporting segment. Beginning with fiscal year 2016 all facilities are reported as an asset based on the segment that acquired the asset as we believe this better reflects total assets of the business segment. In prior fiscal years (which have not been recast in this table), the book value of certain shared facilities was allocated across reporting segments based on usage. Expenses and costs related to these facilities including depreciation expense, are allocated and reported in each reporting segment's operating income for each fiscal year presented.

[3] The fiscal year ended January 31, 2016 includes gains of $611 on disposal of assets related to the exit of contract manufacturing operations.

[4] The fiscal year ended January 31, 2016 includes pre-contract cost write-offs of $2,933, a goodwill impairment loss of $7,413, and a $1,483 reduction of an acquisition-related contingent liability for Vista as a result of changes in expected sales and cash flows.