FAIR VALUE MEASUREMENTS (Tables)

6 Months Ended

Jun. 30, 2011

FAIR VALUE MEASUREMENTS [Abstract]

Liabilities measured at fair value on a recurring basis

	June 30, 2011
	Level 1		Level 2		Level 3		Total
	(Thousands of Dollars)
Accrued compensation expense:
NuStar Energy restricted units and performance awards	$	16,622	$	—	$	—	$	16,622
NuStar Energy unit options	—		4,848		—		4,848
Total	$	16,622	$	4,848	$	—	$	21,470
	December 31, 2010
	Level 1		Level 2		Level 3		Total
	(Thousands of Dollars)
Accrued compensation expense:
NuStar Energy restricted units and performance awards	$	14,968	$	—	$	—	$	14,968
NuStar Energy unit options	—		7,076		—		7,076
Total	$	14,968	$	7,076	$	—	$	22,044

Weighted-average assumptions used in Black-Scholes Option-Pricing Model

	June 30, 2011		December 31, 2010
Expected life in years	6.3		6.3
Expected volatility	19.8	%	23.3	%
Expected distribution yield	6.7	%	6.2	%
Risk-free interest rate	0.3	%	0.4	%