Summary of Significant Accounting Policies (Gain) Loss on the Sale of Trade Receivables (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Jan. 31, 2014	Jan. 31, 2013	Jan. 31, 2012
Sale of Receivables
Total receivables sold	$ 23,617	$ 20,711	$ 30,307
Net proceeds	22,943	20,198	29,146
Discount on sold receivables	(674)	(513)	(1,161)
Unaccreted interest on sold receivables	890	568	1,273
Gain on sale of accounts receivable	216	55	112
Trade accounts receivable
Sale of Receivables
Total receivables sold	11,705	9,617	13,645
Term Receivables Long Term
Sale of Receivables
Total receivables sold	$ 11,912	$ 11,094	$ 16,662