Summary of Significant Accounting Policies - Additional Information (Detail)
12 Months Ended
Dec. 31, 2016
USD ($)
Segment
Dec. 31, 2015
USD ($)
Dec. 31, 2014
USD ($)
Nov. 30, 2014
USD ($)
Accounting Policies [Line Items]        
Original maturity of highly liquid investments three months      
Cash - restricted $ 1,308,000 $ 0    
Impairment of investment   0   $ 0
Allowance for bad debt 70,000 228,000    
Depreciation Expense $ 4,904,000 4,776,000 $ 1,081,000  
Number of operating segment | Segment 3      
Asset Impairment $ 275,000      
Impairment charges 0 0 0  
Uninsured cash balances 3,755,000 4,978,000    
Research and development costs 4,877,000 4,983,000 1,084,000  
Advertising costs $ 1,083,000 $ 847,000 $ 428,000  
Lifting Equipment [Member]        
Accounting Policies [Line Items]        
Reporting unit, percentage of fair value in excess of carrying amount 5.00%      
ASV Segment [Member]        
Accounting Policies [Line Items]        
Reporting unit, percentage of fair value in excess of carrying amount 20.00%      
Equipment Distribution [Member]        
Accounting Policies [Line Items]        
Asset Impairment $ 275,000      
Goodwill Impairment [Member]        
Accounting Policies [Line Items]        
Number of operating segment | Segment 3