Income Taxes (Details) (USD $) In Thousands, unless otherwise specified				12 Months Ended
	Jan. 31, 2014	Jan. 31, 2013	Jan. 31, 2012	Jan. 31, 2014 United States [Member]	Jan. 31, 2014 Canada [Member]
Income Tax Contingency [Line Items]
Pre-tax book income, domestic				$ 62,996
Pre-tax book income, foreign					481
Total unrecognized tax benefits that, if recognized, would affect the company's effective tax rate	3,029	2,738	2,318
Accrued interest and penalties related to unrecognized tax benefits	$ 1,897	$ 1,605	$ 1,379