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

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)
-URI http://asc.fasb.org/extlink&oid=66011266&loc=d3e33918-111571

Name:	us-gaap_EquityMethodInvestmentOwnershipPercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

BASIS OF PRESENTATION (Details) - business		1 Months Ended
BASIS OF PRESENTATION (Details) - business	Nov. 28, 2017	Dec. 31, 2016	Sep. 30, 2017
ParentCo
Related Party Transaction [Line Items]
Number of independent businesses		2
ParentCo \| Subsequent Event
Related Party Transaction [Line Items]
Number of independent businesses	2
Pennsylvania Mining Operations \| CNX Coal Resources LP
Related Party Transaction [Line Items]
Ownership percentage			25.00%