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Commitments and Contingencies - Additional Information (Details)		1 Months Ended		3 Months Ended		9 Months Ended
	Aug. 31, 2010 USD ($) $ / a $ / t	Dec. 31, 2016 USD ($)	Nov. 30, 2016 USD ($)	Sep. 30, 2016 USD ($)	Sep. 30, 2015 USD ($)	Sep. 30, 2016 USD ($)	Sep. 30, 2015 USD ($)	Nov. 01, 2016 Railcar
Loss Contingencies [Line Items]
Expenses related to operating leases and rental agreements				$ 1,765,000	$ 1,316,000	$ 5,202,000	$ 3,124,000
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				0	0	0	841,000
Tonnage fees per ton \| $ / t	0.50
Tonnage fees incurred				71,000	$ 46,000	169,000	$ 213,000
Consulting Agreement \| Minimum
Loss Contingencies [Line Items]
Tonnage fees						$ 200,000
Employment Agreements
Loss Contingencies [Line Items]
Agreements renewal period						1 year
Commitments under employment agreement				1,175,000		$ 1,175,000
Agreement expiration date						2017-05
Performance Bond \| Jackson County, Wisconsin
Loss Contingencies [Line Items]
Bond, carrying value				4,400,000		$ 4,400,000
Permit bond \| Town of Curran, Wisconsin
Loss Contingencies [Line Items]
Bond, carrying value				$ 1,000,000		1,000,000
Customers in Conjunction with Bankruptcy Proceedings
Loss Contingencies [Line Items]
Deferred revenue recognized						$ 4,969,000
Subsequent Event
Loss Contingencies [Line Items]
Number of rail cars \| Railcar								30
Subsequent Event \| 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