Summary of Business and Significant Accounting Policies (Product Warranty Expense) (Details) (USD $) In Thousands, unless otherwise specified				12 Months Ended
	Jan. 31, 2013	Jan. 31, 2012	Jan. 31, 2011	Jan. 31, 2013 Minimum [Member]	Jan. 31, 2013 Maximum [Member]
Warranty [Line Items]
Product warranty period				5 years	10 years
Accrued warranty balance	$ 1,000	$ 1,400	$ 2,300