Financing Arrangements (Details) - USD ($)	12 Months Ended
	Jan. 31, 2016	Jan. 31, 2015	Jan. 31, 2014
Line of Credit Facility [Line Items]
Total rent and lease expense	$ 2,095,000	$ 1,977,000	$ 2,395,000
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
Wells Fargo Bank, N.A. [Member]
Line of Credit Facility [Line Items]
Date of termination of uncollateralized credit agreement		Apr. 15, 2015
Borrowing capacity under line of credit	$ 10,500,000
Maturity date of the line of credit	Nov. 30, 2016
Letters of credit issued, amount	$ 664,000
Borrowing outstanding under line of credit		$ 0	0
Borrowings under the credit line		0	0
JPMorgan Chase Bank [Member]
Line of Credit Facility [Line Items]
Borrowing capacity under line of credit	$ 125,000,000
Date of new credit facility	Apr. 15, 2015
Maturity date of the line of credit	Apr. 15, 2020
Unamortized debt issuance costs	$ 461,000
Annual administrative and unborrowed capacity fees	213,000
Remaining borrowing capacity under the line of credit	125,000,000
Borrowing outstanding under line of credit	0	0	0
Borrowings under the credit line	$ 0	$ 0	$ 0