Gain on Property Insurance Recovery Related to Mountain Laurel Longwall (Details) $ in Thousands	3 Months Ended
Mar. 31, 2020 USD ($)	Jun. 30, 2020 item
Business Interruption Loss [Line Items]
Gain on Business Interruption Insurance Recovery \| $	$ 9,000
Longwall system's not recoverable \| item		123
Hydraulic Shields not recoverable \| item		176
Mountain Laurel Longwall Operations
Business Interruption Loss [Line Items]
Gain on Business Interruption Insurance Recovery \| $	$ 9,000

Represents longwall system's hydraulic shields not recovered as a result of geologic conditions in the final longwall panel.

No definition available.

+ Details

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- Definition

Represents longwall system's not recovered as a result of geologic conditions in the final longwall panel.

+ References

No definition available.

+ Details

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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.

+ Details

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- Definition

The net amount (to the extent disclosed within this portion of the income statement) by which an insurance settlement exceeds incremental costs incurred from the event causing an interruption of business, plus the insurance award for earnings lost from the event, such as a natural catastrophe, explosion or fire.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 30
-Section 50
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=114868897&loc=SL114872001-224240

+ Details

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- Details

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