Goodwill and Other Intangible Assets - Narrative (Detail) (USD $)	12 Months Ended
	Jan. 31, 2013	Jan. 31, 2012	Jan. 31, 2011
Finite-Lived Intangible Assets [Line Items]
Goodwill expected to be tax deductible	$ 1,534,000	$ 1,534,000
Total amortization expense for other intangible assets	$ 3,453,000	$ 4,108,000	$ 2,276,000