Percentage of profit after capital investment and interest is returned

No definition available.

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- Definition

Percentage of profit until capital investment and interest is returned

+ References

No definition available.

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- Definition

Date when the business acquisition agreement was executed, in CCYY-MM-DD format.

+ References

No definition available.

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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- Definition

Amount of consideration transferred, consisting of acquisition-date fair value of assets transferred by the acquirer, liabilities incurred by the acquirer, and equity interest issued by the acquirer.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 30
-Section 30
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- Definition

This element represents the total consolidated (as applicable) capitalization of the entity which is comprised of its long-term debt and equity instruments. The table may be detailed by subsidiary (legal entity) and include information by type of debt or equity detailed by instrument.

+ References

No definition available.

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- Definition

Amount of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. Excludes cash and cash equivalents within disposal group and discontinued operation.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 10
-Section 45
-Paragraph 1
-Subparagraph (a)
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- Definition

Cost incurred related to exploration, development, mining, processing and providing mining support activities related to coal.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.2(a),(d))
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- Definition

Amount of fossil fuel included in inventory classified as other.

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.6(a))
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- Definition

The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 10
-Section 50
-Paragraph 3
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Hourglass Sands (Narrative) (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended		9 Months Ended
	Feb. 28, 2018	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Business Acquisition [Line Items]
Operating costs and expenses		$ 60,230	$ 54,354	$ 145,744	$ 138,125
Cash and cash equivalents		$ 16,903	$ 9,407	$ 16,903	$ 9,407	$ 12,483
Hourglass [Member]
Business Acquisition [Line Items]
Percentage of profit after capital investment and interest is returned		90.00%		90.00%
Capitalization		$ 8,000		$ 8,000
Hourglass [Member] \| Director [Member]
Business Acquisition [Line Items]
Business acquisition purchase price	$ 4,000
Capital Unit, Class A [Member] \| Hourglass [Member]
Business Acquisition [Line Items]
Percentage of profit until capital investment and interest is returned		100.00%		100.00%
Hourglass Sands, LLC [Member]
Business Acquisition [Line Items]
Date of acquisition agreement				Feb. 01, 2018
Business acquisition purchase price	$ 4,000
Cash and cash equivalents		$ 4,200		$ 4,200
Sand inventory		$ 800		$ 800
Hourglass Sands, LLC [Member] \| Hourglass [Member] \| Director [Member]
Business Acquisition [Line Items]
Date of acquisition agreement				Feb. 01, 2018
Hourglass Sands, LLC [Member] \| Capital Unit, Class A [Member] \| Hourglass [Member]
Business Acquisition [Line Items]
Equity method investment ownership percentage		100.00%		100.00%