Warranties (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Oct. 31, 2013	Oct. 31, 2012	Oct. 31, 2013	Oct. 31, 2012
Product Warranty Accrual [Roll Forward]
Beginning balance	$ 2,047	$ 1,949	$ 1,888	$ 1,699
Accrual for warranties	1,086	628	2,818	2,226
Settlements made (in cash or in kind)	(923)	(698)	(2,496)	(2,046)
Ending balance	$ 2,210	$ 1,879	$ 2,210	$ 1,879