Quarterly report pursuant to Section 13 or 15(d)

Marketable Securities and Fair Value - Additional Information (Detail)

v3.8.0.1
Marketable Securities and Fair Value - Additional Information (Detail) - USD ($)
3 Months Ended 9 Months Ended
Sep. 30, 2017
Sep. 30, 2016
Sep. 30, 2017
Sep. 30, 2016
Dec. 31, 2016
Investments Debt And Equity Securities [Abstract]          
Realized gain or losses $ 0 $ 0 $ 0 $ 0  
Long-term debt, carrying value $ 4,100,000   $ 4,100,000   $ 5,600,000
Shares of common stock to be purchased with warrants 377,273   377,273