CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS)
Equity in earnings (loss) of NuStar Energy L.P.	$ 12,144	$ 11,772
General and administrative expenses	(800)	(857)
Other income (expense), net	81	136
Interest expense, net	(173)	(133)
Income (loss) before income tax (expense) benefit	11,252	10,918
Income tax (expense) benefit	(177)	128
Net income (loss)	11,075	11,046
Comprehensive income (loss)	$ 11,272	$ 5,286
Basic net income (loss) per unit	$ 0.26	$ 0.26
Diluted net income (loss) per unit	$ 0.26	$ 0.26
Weighted-average number of basic units outstanding	42,605,668	42,574,419
Weighted-average number of diluted units outstanding	42,605,668	42,597,641