VARIABLE INTEREST ENTITIES - UNCONSOLIDATED VARIABLE INTEREST ENTITIES (Narrative) (Details) - Variable Interest Entity, Not Primary Beneficiary	1 Months Ended
Dec. 31, 2018
Variable Interest Entity [Line Items]
Direct common interest (as a percent)	22.80%
Gray Oak Holdings LLC
Variable Interest Entity [Line Items]
Direct common interest (as a percent)	35.00%

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://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 810
-SubTopic 10
-Section 50
-Paragraph 5A
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=118582676&loc=SL6759159-111685

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