Warranties (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Oct. 31, 2014	Oct. 31, 2013	Oct. 31, 2014	Oct. 31, 2013
Product Warranty Accrual [Roll Forward]
Beginning balance	$ 2,617	$ 2,047	$ 2,525	$ 1,888
Accrual for warranties	676	1,086	2,065	2,818
Settlements made (in cash or in kind)	(837)	(923)	(2,134)	(2,496)
Ending balance	$ 2,456	$ 2,210	$ 2,456	$ 2,210