ACQUISITIONS (Details) (Alliance Resource Properties, Acquisition of coal reserves from Laurel Run Mining Company, USD $) In Millions, unless otherwise specified	1 Months Ended
Jun. 30, 2013 T
Alliance Resource Properties \| Acquisition of coal reserves from Laurel Run Mining Company
Asset Acquisition
Coal reserves, rights purchased (in tons)	11,600,000
Additional coal resources (in tons)	5,900,000
Purchase price	$ 25.2

The cash outflow from the acquisition of a mineral right which is the right to extract a mineral from the earth or to receive payment, in the form of royalty, for the extraction of minerals.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Investing Activities

-URI http://asc.fasb.org/extlink&oid=6516133

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 13

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3213-108585

Name:	us-gaap_PaymentsToAcquireMineralRights
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration