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Commitments and Contingencies - Additional Information (Detail)
3 Months Ended 12 Months Ended
Aug. 01, 2010
USD ($)
Mar. 31, 2018
USD ($)
$ / Ton
Mar. 31, 2017
USD ($)
Jul. 31, 2016
USD ($)
Dec. 31, 2017
USD ($)
Loss Contingencies [Line Items]          
Expenses related to operating leases and rental agreements   $ 2,705,000 $ 1,975,000    
Capital required as well as future expansion projects   18,900,000      
Restricted cash   487,000     $ 487,000
Permit bond          
Loss Contingencies [Line Items]          
Bond, carrying value   1,350,000      
Jackson County, Wisconsin | Performance Bond          
Loss Contingencies [Line Items]          
Bond, carrying value   4,400,000      
Monroe County, Wisconsin | Performance Bond          
Loss Contingencies [Line Items]          
Bond, carrying value   900,000      
Pipeline Common Carrier | Performance Bond          
Loss Contingencies [Line Items]          
Bond, carrying value   1,943,000      
Restricted cash   487,000     $ 487,000
Consulting Agreement          
Loss Contingencies [Line Items]          
Closing fee per acre $ 1,000        
Consulting fees expenses reimbursements and closing cost   $ 60,000 3,000    
Tonnage fees per ton | $ / Ton   0.5      
Tonnage fees incurred   $ 164,000 $ 117,000    
Consulting Agreement | Minimum          
Loss Contingencies [Line Items]          
Tonnage fees       $ 200,000