Acquisitions - Allocations of Diberil Purchase Price (Detail) (USD $) In Thousands, unless otherwise specified	Oct. 31, 2013	Jan. 31, 2013	May 30, 2012 Diberil Sociedad Anonima [Member]
Business Acquisition [Line Items]
Working capital			$ 3,592
Property and equipment			33,500
Goodwill	8,915	23,561	4,025
Other intangible assets			1,000
Other assets			9,131
Other noncurrent liabilities			(16,981)
Total purchase price			$ 34,267