CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS)
Equity in earnings (loss) of NuStar Energy L.P.	$ 14,390	$ 12,144
General and administrative expenses	(872)	(800)
Other income (expense), net	17	81
Interest expense, net	(222)	(173)
Income (loss) before income tax (expense) benefit	13,313	11,252
Income tax (expense) benefit	333	(177)
Net income (loss)	13,646	11,075
Comprehensive income (loss)	$ 12,698	$ 11,272
Basic net income (loss) per unit	$ 0.32	$ 0.26
Diluted net income (loss) per unit	$ 0.32	$ 0.26
Weighted-average number of basic units outstanding	42,656,281	42,605,668
Weighted-average number of diluted units outstanding	42,656,281	42,605,668