Estimated fair value of warrant.

No definition available.

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- Definition

Agreed upon price for the exchange of the underlying asset.

+ References

No definition available.

+ Details

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- Definition

Period the instrument, asset or liability is expected to be outstanding, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

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- Definition

Measure of dispersion, in percentage terms (for instance, the standard deviation or variance), for a given stock price.

+ References

No definition available.

+ Details

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- Definition

Percentage of risk free interest rate

+ References

No definition available.

+ Details

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- References

No definition available.

+ Details

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- Definition

The carrying amount of a liability for an asset retirement obligation. An asset retirement obligation is a legal obligation associated with the disposal or retirement of a tangible long-lived asset that results from the acquisition, construction or development, or the normal operations of a long-lived asset, except for certain obligations of lessees.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 410
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=6392692&loc=d3e7535-110849

+ Details

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Balance Type:	credit
Period Type:	instant

- Definition

A general description of the asset retirement obligations and the associated long-lived assets. Description may include the terms of the legal restriction.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 410
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=6392692&loc=d3e7535-110849

+ Details

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- Details

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Fair Value Measurements (Details Textual) - USD ($)				12 Months Ended
Fair Value Measurements (Details Textual) - USD ($)	Nov. 01, 2017	Apr. 03, 2017	Feb. 15, 2017	Dec. 31, 2018	Dec. 31, 2017
Fair Value Measurements (Textual)
Asset retirement obligation				$ 13,700,000
Asset retirement obligation, description				The estimated timing of reclamation ranging from one to 75 years based on estimates from reserve engineers; an inflation rate between 1.92% to 2.10%; and a credit adjusted risk-free rate between 7.24% to 8.13%, which takes into account our credit risk and the time value of money.
Class A Units [Member] \| California Warrant [Member] \| Maximum [Member]
Fair Value Measurements (Textual)
Fair value of warrant				$ 45,000
Class A Units [Member] \| California Warrant [Member] \| Minimum [Member]
Fair Value Measurements (Textual)
Fair value of warrant				20,000
Level 3 [Member]
Fair Value Measurements (Textual)
Asset retirement obligation				$ 13,700,000
Level 3 [Member] \| California Warrant [Member]
Fair Value Measurements (Textual)
Fair value of warrant			$ 5,800,000
Volatility rate			41.80%
Risk-free rate			2.30%
Exercise price			$ 7.20
Term			7 years
Level 3 [Member] \| Appalachia Warrant [Member]
Fair Value Measurements (Textual)
Fair value of warrant		$ 1,300,000
Volatility rate		39.30%
Risk-free rate		2.10%
Exercise price		$ 7.20
Level 3 [Member] \| Class A Units [Member] \| California Warrant [Member]
Fair Value Measurements (Textual)
Fair value of warrant					$ 2,000,000
Volatility rate					45.00%
Risk-free rate					2.10%
Exercise price					$ 7.20
Term					6 years 4 months 24 days
Level 3 [Member] \| Class A Units [Member] \| Appalachia Warrant [Member]
Fair Value Measurements (Textual)
Volatility rate	45.00%
Risk-free rate	2.10%
Exercise price	$ 7.20
Term	6 years 6 months