Investment - Additional Information (Detail) (USD $)
In Thousands, except Share data, unless otherwise specified
12 Months Ended
Dec. 31, 2014
Dec. 31, 2013
Schedule of Cost-method Investments [Line Items]    
Investments, at cost $ 250 $ 250
Licensing Agreements    
Schedule of Cost-method Investments [Line Items]    
Number of Common stock received in connection with license agreement 57,000  
Investments, at cost $ 250