Quarterly report pursuant to Section 13 or 15(d)

Stockholders' Equity - Additional Information (Detail)

v3.2.0.727
Stockholders' Equity - Additional Information (Detail) - USD ($)
 3 Months Ended 6 Months Ended 12 Months Ended
Jun. 15, 2015
Jun. 10, 2015
May. 15, 2015
Jun. 30, 2015
Jun. 30, 2015
Dec. 31, 2014
Apr. 02, 2014
Subsidiary, Sale of Stock [Line Items]              
Common stock shares issued       9,060,314 9,060,314 7,753,717  
Follow-on Offering [Member]              
Subsidiary, Sale of Stock [Line Items]              
Common stock, shares issued       1,306,597      
Price per share       $ 11.40 $ 11.40    
2015 Follow-on Offering [Member]              
Subsidiary, Sale of Stock [Line Items]              
Gross proceeds from issuance of common stock     $ 14,300,000        
Common stock, shares issued     1,250,000        
Price per share     $ 11.40        
Net proceeds after deducting offering expenses     $ 13,200,000        
Over-Allotment Option [Member]              
Subsidiary, Sale of Stock [Line Items]              
Gross proceeds from issuance of common stock $ 645,000            
Net proceeds after deducting offering expenses $ 606,000            
Additional common stock shares issued   56,597          
Maximum [Member]              
Subsidiary, Sale of Stock [Line Items]              
Securities allowed for issuance             $ 300,000,000
Common Stock [Member]              
Subsidiary, Sale of Stock [Line Items]              
Gross proceeds from issuance of common stock         $ 15,000,000    
Common stock, shares issued         1,306,597 1,223,453  
Common Stock [Member] | Universal Registration Statement [Member]              
Subsidiary, Sale of Stock [Line Items]              
Common stock shares issued       1,223,453 1,223,453