Represents the amount of accrued contingent liability for reclamation obligations.

No definition available.

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- Definition

Represents the number of reclamation obligations related to discontinued operations for which the entity remains contingently liable.

+ References

No definition available.

+ Details

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- Definition

Represents the estimated forfeiture rates on stock-based awards.

+ References

No definition available.

+ Details

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- Definition

The percentage of total revenue generated from services.

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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.

+ Details

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- Definition

Amount charged to advertising expense for the period, which are expenses incurred with the objective of increasing revenue for a specified brand, product or product line.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 720
-SubTopic 35
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6420018&loc=d3e36677-107848

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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://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 410
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (c)
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Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Asset Retirement Obligation
-URI http://asc.fasb.org/extlink&oid=6505190

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- Definition

For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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-Name Accounting Standards Codification
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-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=73719730&loc=d3e13537-108611

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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
-Topic 323
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (a)(1)
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- Definition

The parent entity's interest in net assets of the subsidiary, expressed as a percentage.

+ References

No definition available.

+ Details

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Data Type:	num:percentItemType
Balance Type:	na
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- Definition

Number of segments reported by the entity. A reportable segment is a component of an entity for which there is an accounting requirement to report separate financial information on that component in the entity's financial statements.

+ References

No definition available.

+ Details

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- Details

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Summary of Significant Accounting Policies (Details) $ in Millions	12 Months Ended
	Sep. 30, 2016 USD ($) segment item	Sep. 30, 2015 USD ($)	Sep. 30, 2014 USD ($)
Summary of Significant Accounting Policies
Number of business segments \| segment	3
Percentage of revenue from services	9.00%	9.00%	10.00%
Asset retirement obligations	$ 0.0	$ 0.0
Number of reclamation obligations \| item	1
Advertising costs	$ 11.7	10.0	$ 10.3
Coal Cleaning Business
Summary of Significant Accounting Policies
Number of reclamation obligations \| item	1
Accrued liability for reclamation obligations	$ 9.3	$ 7.4
Minimum
Summary of Significant Accounting Policies
Economic interest	20.00%
Estimated forfeiture rates	1.00%
Maximum
Summary of Significant Accounting Policies
Economic interest	50.00%
Ownership percentage - cost method	20.00%
Maximum \| Revenue \| Customer Concentration Risk
Summary of Significant Accounting Policies
Revenue accounted for, percentage	10.00%
Maximum \| Revenue \| Geographic Concentration Risk
Summary of Significant Accounting Policies
Revenue accounted for, percentage	10.00%