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, 2013	Jan. 31, 2012	Jan. 31, 2011
Sale of Receivables [Line Items]
Receivables Sold on Non Recourse Basis	$ 20,711	$ 30,307	$ 53,565
Proceeds from Sale of Finance Receivables	20,198	29,146	51,601
Discount on Sold Receivables	(513)	(1,161)	(1,964)
Unaccreted Interest on Sold Receivables	568	1,273	2,133
Gain (Loss) on Sale of Accounts Receivable	55	112	169
Trade accounts receivable
Sale of Receivables [Line Items]
Receivables Sold on Non Recourse Basis	9,617	13,645	27,011
Term Receivables Long Term [Member]
Sale of Receivables [Line Items]
Receivables Sold on Non Recourse Basis	$ 11,094	$ 16,662	$ 26,554