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Commitments and Contingencies - Additional Information (Detail)
 1 Months Ended 12 Months Ended
Aug. 31, 2010
USD ($)
$ / a
Dec. 31, 2016
USD ($)
Nov. 30, 2016
USD ($)
Dec. 31, 2017
USD ($)
$ / t
Dec. 31, 2016
USD ($)
Jul. 31, 2016
USD ($)
Dec. 31, 2015
USD ($)
Loss Contingencies [Line Items]              
Expenses related to operating leases and rental agreements       $ 10,239,000 $ 7,065,000   $ 4,098,000
Capital requirements for Oakdale facility as well as future expansion projects       35,100,000      
Restricted cash   $ 971,000   487,000 971,000    
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 [Member] | Performance Bond              
Loss Contingencies [Line Items]              
Bond, carrying value       1,943,000      
Restricted cash   971,000   487,000 971,000    
Consulting Agreement              
Loss Contingencies [Line Items]              
Reimbursed out-of-pocket and other expenses $ 10,000            
Closing fee per acre | $ / a 1            
Consulting fees, expenses reimbursements and closing costs       $ 19,000 0   841,000
Tonnage fees per ton | $ / t       0.50      
Tonnage fees incurred       $ 530,000 $ 258,000   $ 252,000
Consulting Agreement | Minimum              
Loss Contingencies [Line Items]              
Tonnage fees           $ 200,000  
Customers in Conjunction with Bankruptcy Proceedings              
Loss Contingencies [Line Items]              
Unsecured bankruptcy claim granted     $ 12,000,000        
Purchase of unsecured bankruptcy claim by third party   $ 6,600,000