Quarterly report pursuant to Section 13 or 15(d)

Fair Value Measurements - Additional Information (Detail)

v3.5.0.2
Fair Value Measurements - Additional Information (Detail) - USD ($)
3 Months Ended 9 Months Ended
Oct. 31, 2016
Oct. 31, 2016
Jan. 31, 2016
Oct. 31, 2015
Fair Value Measurements Disclosure [Line Items]        
Fair value measurements of our financial assets and liabilities $ 12,991,000 $ 12,991,000 $ 15,922,000  
Assets measured at fair value on nonrecurring basis 0 0   $ 0
Loss on impairment of long-lived assets 99,000 99,000    
Other-than-temporary impairment 0 $ 0    
Maximum maturity of marketable securities   Three months or less    
Cash equivalents and marketable securities 37,900,000 $ 37,900,000 71,100,000  
Restricted cash related to performance obligations 108,000 108,000 82,000  
Fair Value, Inputs, Level 3 [Member]        
Fair Value Measurements Disclosure [Line Items]        
Fair value measurements of our financial assets and liabilities 0 0 0  
Cash Related to Performance Obligations [Member]        
Fair Value Measurements Disclosure [Line Items]        
Restricted cash related to performance obligations $ 100,000 $ 100,000 $ 100,000