CREDIT FACILITY Narrative (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Jun. 27, 2017	Jun. 16, 2016
Line of Credit Facility [Line Items]
General partner interest percentage	2.00%	2.00%
Outstanding borrowings	$ 42,500,000	$ 30,000,000
Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Initiation date	Jun. 28, 2013
Maturity date	Jun. 27, 2018
Borrowing capacity			$ 60,000,000	$ 50,000,000.0
Letters of credit capacity			$ 10,000,000
Collateral	Our obligations under our revolving credit facility are guaranteed by Riverwalk Holdings, LLC (Riverwalk), our wholly owned subsidiary. Riverwalk has pledged a total of 2,926,833 NuStar Energy common units that it owns to secure its guarantee.
Outstanding borrowings	$ 42,500,000
Borrowing availability	$ 17,500,000
Interest rate description	Interest on our revolving credit facility is based upon, at our option, either an alternative base rate or a LIBOR-based rate
Interest rate	3.60%	2.80%
Deferred debt costs	$ 100,000	$ 100,000
Revolving Credit Facility [Member] | NuStar Energy Consolidated Debt Coverage Ratio [Member]
Line of Credit Facility [Line Items]
Covenant terms	The revolving credit facility contains customary restrictive covenants, such as limitations on indebtedness, liens, dispositions of material property, mergers, asset transfers and certain investing activities. In addition, the revolving credit facility requires NuStar Energy to comply with the financial covenant contained in NuStar Logistics revolving credit facility.
Revolving Credit Facility [Member] | Cash Distributions Covenant [Member]
Line of Credit Facility [Line Items]
Covenant terms	We are also required to receive cash distributions each fiscal quarter of at least $19.0 million in respect of our ownership interests in NuStar Energy.