RELATED PARTY TRANSACTIONS Narrative (Details)	6 Months Ended
Jun. 30, 2018
Related Party Transactions [Abstract]
Administrative fees, description	(the Amended GP Services Agreement), which provided that we furnish administrative services necessary to conduct the business of NuStar GP Holdings, and NuStar GP Holdings compensated us for these services for an annual fee of $1.0 million, subject to adjustment. We terminated the Amended GP Services Agreement in conjunction with the Merger.

Description of the nature of payments to a managing member or general partner, affiliate of a managing member or general partner, or affiliate of a limited liability company (LLC) or limited partnership (LP) for administrative services provided to the LLC or LP, for example, but is not limited to, salaries, rent, or other overhead costs. Includes a description of the services performed and the amount reimbursed for such services.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 850
-SubTopic 10
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39549-107864

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration