Financing Arrangements (Details) - USD ($)	12 Months Ended
	Jan. 31, 2017	Jan. 31, 2016	Jan. 31, 2015
Line of Credit Facility [Line Items]
Debt Instrument, Covenant Compliance	The Company requested and received the necessary covenant waivers relating to its late filing of financial information in fiscal 2017. Financial covenants include an interest coverage ratio and funded indebtedness to earnings before interest, taxes, depreciation, and amortization as defined in the Credit Agreement. The Company is in compliance with all financial covenants set forth in the Credit Agreement.
Total rent and lease expense	$ 2,028,000	$ 2,095,000	$ 1,977,000
Integra Plastics [Member]
Line of Credit Facility [Line Items]
Borrowing outstanding under line of credit	0	0	0
SBG Innovatiie and affiliate [Member]
Line of Credit Facility [Line Items]
Borrowing outstanding under line of credit	$ 0	$ 0	0
JPMorgan Chase Bank [Member]
Line of Credit Facility [Line Items]
Date of new credit facility	Apr. 15, 2015	Apr. 15, 2015
Borrowing capacity under line of credit	$ 125,000,000	$ 125,000,000
Maturity date of the line of credit	Apr. 15, 2020	Apr. 15, 2020
Unamortized debt issuance costs	$ 352,000	$ 461,000	0
Annual administrative and unborrowed capacity fees	215,000	213,000	0
Letters of credit issued, amount	464,000
Remaining borrowing capacity under the line of credit	124,536,000
Borrowing outstanding under line of credit	0	0	0
Borrowings under the credit line	0	0	0
Wells Fargo Bank, N.A. [Member]
Line of Credit Facility [Line Items]
Borrowing capacity under line of credit			$ 10,500,000
Date of termination of uncollateralized credit agreement			Nov. 30, 2016
Letters of credit issued, amount	$ 50,000	664,000
Borrowing outstanding under line of credit		0	$ 0
Borrowings under the credit line		$ 0	$ 0