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Stock-Based Compensation - Summary of Change in Number of Non-Vested Options to Purchase Shares of Common Stock (Detail) (USD $) | 12 Months Ended
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Jan. 31, 2014 | Jan. 31, 2013 | Jan. 31, 2012
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract] |  |  |
Shares, Nonvested, Beginning balance | 388,500 | 212,500 | 237,000
Shares, Granted | 303,000 | 293,000 | 212,500
Shares, Vested | (384,500) | (112,000) | (232,000)
Shares, Forfeited (non-vested) | (4,000) | (5,000) | (5,000)
Shares, Nonvested, Ending balance | 303,000 | 388,500 | 212,500
Weighted Average Fair Value, Nonvested, Beginning balance | $ 5.67 | $ 5.09 | $ 6.31
Weighted Average Fair Value, Granted | $ 4.40 | $ 5.65 | $ 5.09
Weighted Average Fair Value, Vested | $ 5.67 | $ 4.51 | $ 6.34
Weighted Average Fair Value, Forfeited (non-vested) | $ 5.71 | $ 6.32 | $ 4.98
Weighted Average Fair Value, Nonvested, Ending balance | $ 4.40 | $ 5.67 | $ 5.09

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- Definition No authoritative reference available. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (d)(1) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
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