Quarterly report pursuant to Section 13 or 15(d)

Fair Value Measurements - Additional Information (Detail)

v3.10.0.1
Fair Value Measurements - Additional Information (Detail) - USD ($)
3 Months Ended 6 Months Ended
Jul. 31, 2018
Jul. 31, 2018
Jan. 31, 2018
Jul. 31, 2017
Fair Value Measurements Disclosure [Line Items]        
Fair value measurements of our financial assets and liabilities $ 13,074,000 $ 13,074,000 $ 13,008,000  
Impairment charges on goodwill 0      
Impairment charges on other long-lived assets 0      
Maximum maturity of marketable securities   Three months or less    
Cash equivalents and marketable securities 35,000,000 $ 35,000,000 52,100,000  
Restricted cash 547,000 547,000 9,000 $ 8,000
Fair Value, Inputs, Level 3 [Member]        
Fair Value Measurements Disclosure [Line Items]        
Fair value measurements of our financial assets and liabilities $ 0 $ 0 $ 0