Quarterly report pursuant to Section 13 or 15(d)

Intangible Assets and Goodwill - Additional Information (Detail)

v3.10.0.1
Intangible Assets and Goodwill - Additional Information (Detail) - USD ($)
3 Months Ended 6 Months Ended 9 Months Ended
Sep. 30, 2018
Sep. 30, 2017
Jun. 30, 2018
Sep. 30, 2018
Sep. 30, 2017
Dec. 31, 2017
Goodwill And Intangible Assets Disclosure [Abstract]            
Intangible assets and goodwill impairment     $ 0      
Amortization expense $ 0 $ 0   $ 0 $ 0  
Goodwill $ 2,926,000     $ 2,926,000   $ 2,926,000