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Summary of Significant Accounting Policies - Additional Information (Details) $ in Thousands		3 Months Ended		6 Months Ended
	Aug. 07, 2019 USD ($)	Jun. 30, 2019 USD ($) shares	Jun. 30, 2018 USD ($) shares	Jun. 30, 2019 USD ($) segment shares	Jun. 30, 2018 USD ($) shares	Aug. 09, 2019 USD ($)	Jan. 01, 2019 USD ($)	Dec. 31, 2018 USD ($)
Significant Accounting Policies [Line Items]
Number of Reportable Segments \| segment				1
Options and warrants excluded from the calculation of diluted shares \| shares		4,690,197	785,697	4,690,197	785,697
Production and importation permission description				22 million pounds in 2015 and was reduced by approximately 4.5 million pounds each year ending at zero in 2020.
Revenue from Contract with Customer, Including Assessed Tax		$ 56,011	$ 57,831	$ 90,675	$ 100,259
Operating Loss Carryforwards		45,900		$ 45,900
Operating Loss Carryforwards, Limitations on Use				(subject to annual limitations of 80% of tax earnings) and $5.4 million expire through 2023 (subject to annual limitations of approximately $1.3 million).
Deferred Tax Assets, Valuation Allowance								$ 11,300
Concentration Risk, Customer				there was one customer accounting for 13% of the Company's revenues.	there were no customers that accounted for 10% or more of the Company's revenues.
Operating Lease, Liability		7,053		$ 7,053
Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount				17,300
PNC Facility [Member]
Significant Accounting Policies [Line Items]
Contractual Obligation		21,000		21,000
No Expiration [Member]
Significant Accounting Policies [Line Items]
Operating Loss Carryforwards		40,500		40,500
State and Local Jurisdiction [Member]
Significant Accounting Policies [Line Items]
Operating Loss Carryforwards		23,500		23,500
Accounting Standards Update 2016-09 [Member]
Significant Accounting Policies [Line Items]
Operating Lease, Liability							$ 8,100
Financial Service [Member]
Significant Accounting Policies [Line Items]
Revenue from Contract with Customer, Including Assessed Tax				1,200	$ 1,200
Customer
Significant Accounting Policies [Line Items]
Accounts Receivable, net		$ 2,800		$ 2,800
Subsequent Event [Member] \| Working Capital Adjustments by Airgas, Inc [Member]
Significant Accounting Policies [Line Items]
Loss Contingency, Receivable						$ 9,500
Loss Contingency, Receivable, From Undisputed Items						3,500
Loss Contingency, Receivable, From Disputed Items						$ 6,000
Litigation Settlement, Amount Awarded from Other Party	$ 8,900