CREDIT FACILITY Narrative (Details)	9 Months Ended
	Sep. 30, 2015 USD ($)	Dec. 31, 2014 USD ($)
Line of Credit Facility [Line Items]
Outstanding borrowings	$ 26,000,000	$ 26,000,000
Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Borrowing capacity	50,000,000.0
Letters of credit capacity	$ 10,000,000.0
Collateral	Our obligations under our revolving credit facility are guaranteed by Riverwalk Holdings, LLC (Riverwalk), a wholly owned subsidiary. Riverwalk pledged 1,792,918 NuStar Energy units that it owns to secure its guarantee.
Outstanding borrowings	$ 26,000,000
Borrowing availability	$ 24,000,000
Weighted-average interest rate	2.30%
Revolving Credit Facility [Member] | NuStar Energy Consolidated Debt Coverage Ratio [Member]
Line of Credit Facility [Line Items]
Covenant terms	In addition, the revolving credit facility requires NuStar Energy to maintain, as of the end of each rolling period of four consecutive fiscal quarters, a consolidated debt coverage ratio not to exceed 5.00-to-1.00. However, if NuStar Energy consummates one or more acquisitions for an aggregate net consideration of at least $50.0 million, the maximum consolidated debt coverage ratio will increase to 5.50-to-1.00 for two rolling periods.
NuStar Energy's consolidated debt coverage ratio	4.4
Revolving Credit Facility [Member] | Cash Distributions Covenant [Member]
Line of Credit Facility [Line Items]
Covenant terms	We are also required to receive cash distributions of at least $16.0 million in respect of our ownership interests in NuStar Energy each fiscal quarter