Segment Information (Details 1) (USD $) In Thousands, unless otherwise specified	3 Months Ended				6 Months Ended
	Jul. 31, 2014		Jul. 31, 2013		Jul. 31, 2014		Jul. 31, 2013		Jan. 31, 2014
Geographic segment data
Net sales	$ 143,591		$ 138,301		$ 264,512		$ 248,311
Operating Income	17,168		17,040		28,089		27,045
Total Assets	591,443		543,641		591,443		543,641		578,610
Long-Lived Assets	46,141		47,296		46,141		47,296		47,796
United States
Geographic segment data
Net sales	78,128	[1]	72,506	[1]	140,407	[1]	130,397	[1]
Operating Income	5,254	[1]	367	[1]	4,410	[1]	2,520	[1]
Total Assets	237,558		225,167		237,558		225,167		239,890
Long-Lived Assets	25,169		25,553		25,169		25,553		25,943
International
Geographic segment data
Net sales	65,463	[2]	65,795	[2]	124,105	[2]	117,914	[2]
Operating Income	11,914	[2]	16,673	[2]	23,679	[2]	24,525	[2]
Total Assets	353,885		318,474		353,885		318,474		338,720
Long-Lived Assets	$ 20,972		$ 21,743		$ 20,972		$ 21,743		$ 21,853

[1] The United States operating income includes unallocated corporate expenses for the three and six months ended July 31, 2014 and 2013.

[2] The International operating income includes certain intercompany profits related to the Company’s supply chain operations for the three and six months ended July 31, 2014 and 2013.