Business Segments and Major Customer Information (Details) (One Customer [Member])	12 Months Ended
Jan. 31, 2013 Engineered Films [Member]	Jan. 31, 2012 Engineered Films [Member]	Jan. 31, 2011 Aerostar [Member]	Jan. 31, 2012 Aerostar [Member]
Segment Reporting Information [Line Items]
Entity-Wide Revenue, Major Customer, Amount	11.00%	10.00%	13.00%
Receivables from major customer, percentage	3.00%	1.00%	11.00%	10.00%

Percentage of revenue generated from a single external customer that accounts for 10 percent or more of an entity's revenues.

No definition available.

Name:	us-gaap_EntityWideRevenueMajorCustomerPercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration