Percentage of the Variable Interest Entity's (VIE) voting interest owned by (or beneficial interest in) the reporting entity (directly or indirectly).

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 810
-SubTopic 10
-Section 50
-Paragraph 5A
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=77990344&loc=SL6759159-111685

Name:	us-gaap_VariableInterestEntityOwnershipPercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

VARIABLE INTEREST ENTITIES - UNCONSOLIDATED VARIABLE INTEREST ENTITIES (Narrative) (Details)	1 Months Ended	6 Months Ended	12 Months Ended
	Jun. 30, 2017	Dec. 31, 2017	Dec. 31, 2017
Sabal Trail
Variable Interest Entity [Line Items]
Direct common interest (as a percent)			50.00%
Nexus
Variable Interest Entity [Line Items]
Direct common interest (as a percent)			50.00%
PennEast
Variable Interest Entity [Line Items]
Direct common interest (as a percent)	10.00%	20.00%