ORGANIZATION Narrative 1 (Details)	Dec. 31, 2017 shares
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Percent ownership interest in NuStar Energy	13.00%
Percent of incentive distribution rights issued by NuStar Energy	100.00%
Incentive distribution rights maximum cash percentage	23.00%
Common units of NuStar Energy	10,214,626