Goodwill and Other Intangible Assets - Additional Information (Detail) - USD ($)	3 Months Ended		6 Months Ended
	Jul. 31, 2015	Jul. 31, 2014	Jul. 31, 2015	Jul. 31, 2014	Jan. 31, 2015
Finite-Lived Intangible Assets [Line Items]
Goodwill	$ 5,579,000		$ 5,579,000		$ 5,594,000
Goodwill impairment			0
Aggregate amortization expense	$ 430,000	$ 364,000	$ 853,000	$ 524,000
Maximum [Member]
Finite-Lived Intangible Assets [Line Items]
Useful life of intangible assets			15 years
Minimum [Member]
Finite-Lived Intangible Assets [Line Items]
Useful life of intangible assets			8 years