Quarterly report pursuant to Section 13 or 15(d)

Property, Plant, and Equipment - Additional Information (Detail)

v3.8.0.1
Property, Plant, and Equipment - Additional Information (Detail) - USD ($)
3 Months Ended 9 Months Ended
Sep. 30, 2017
Sep. 30, 2016
Sep. 30, 2017
Sep. 30, 2016
Property Plant And Equipment [Line Items]        
Depreciation and amortization expenses $ 310,000 $ 274,000 $ 887,000 $ 734,000
Assets Held Under Capital Lease        
Property Plant And Equipment [Line Items]        
Capital leased assets, Gross 378,000   378,000  
Accumulated depreciation related to assets held under capital lease $ 340,000   $ 340,000