Acquisitions - Aggregate Purchase Price (Detail) (USD $)	Jan. 31, 2013	Jan. 31, 2012	Jul. 27, 2010 Intevras Technologies [Member]	Oct. 22, 2010 Bencor [Member]	Jan. 31, 2011 Intevras and Bencor [Member]
Business Acquisition [Line Items]
Cash purchase price			$ 5,500,000	$ 32,073,000	$ 37,573,000
Contingent consideration			1,100,000		1,100,000
Total purchase price			6,600,000	32,073,000	38,673,000
Escrow deposits	$ 2,861,000	$ 443,000	$ 550,000	$ 3,000,000	$ 3,550,000