INVESTMENT IN NUSTAR ENERGY Table 4 (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Reconciliation of NuStar Energy’s total partners’ equity to our investment in NuStar Energy
NuStar GP Holdings’ ownership interest in NuStar Energy	13.00%
NuStar GP Holdings’ share of NuStar Energy’s partners’ equity	$ 220,606	$ 204,803
Step-up in basis related to NuStar Energy’s assets and liabilities, including equity method goodwill, and other	59,115	63,939
Investment in NuStar Energy	279,721	268,742
NuStar Energy LP [Member]
Reconciliation of NuStar Energy’s total partners’ equity to our investment in NuStar Energy
NuStar Energy’s partners’ equity	2,480,089	1,611,617
NuStar Energy's preferred limited partners' equity	756,603	218,400
NuStar Energy's partners' equity, excluding preferred limited partners' equity	$ 1,723,486	$ 1,393,217
NuStar GP Holdings’ ownership interest in NuStar Energy	12.80%	14.70%