UNIT-BASED COMPENSATION (Tables)

12 Months Ended

Dec. 31, 2017

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

NSH restricted units award activity under the 2006 Long-Term Incentive Plan

The following table summarizes information related to outstanding NSH restricted units awarded under the LTI Plan:

	Restricted Unit Grants to Employees		Restricted Unit Grants to Non- Employee Directors		Total		Weighted- Average Grant-Date Fair Value Per Unit
Balance as of January 1, 2015	39,090		20,425		59,515		$	31.13
Granted	26,240		12,814		39,054		$	23.80
Vested	(11,403	)	(10,086	)	(21,489	)	$	30.80
Balance as of December 31, 2015	53,927		23,153		77,080		$	27.51
Granted	32,456		12,126		44,582		$	25.42
Vested	(15,251	)	(11,637	)	(26,888	)	$	28.23
Balance as of December 31, 2016	71,132		23,642		94,774		$	26.32
Granted	45,965		22,042		68,007		$	15.40
Vested	(19,890	)	(11,282	)	(31,172	)	$	27.10
Balance as of December 31, 2017	97,207		34,402		131,609		$	20.49

Schedule of restricted unit awards

The following table presents supplemental information regarding our restricted unit awards:

	Year Ended December 31,
	2017		2016		2015
	(Thousands of Dollars, Except Unit Data)
DERs paid to restricted unitholders	$	206	$	167	$	129
Fair value of restricted units that vested during the period	$	477	$	700	$	379
Units issued for settlement of awards vested, net of employee tax withholding requirements	25,383		21,200		17,272

The number of awards granted under the 2000 Long-Term Incentive Plan

The following table summarizes information about awards we granted under the 2000 LTIP, prior to the Employee Transfer:

		Awards Granted
		Year Ended December 31,
	Vesting		2016	2015
2000 LTIP:
Performance units	(a)		47,646	29,633
Restricted units	1/5 per year		—	250,563
Restricted units (grants to non-employee directors of NuStar GP, LLC)	1/3 per year		—	7,553

(a) Performance units vest 1/3 per year if certain performance measures are met, as defined in the award agreements.

Summary of long-term incentive plan compensation expenses

The following table summarizes information pertaining to long-term incentive plan compensation expense:

	Year Ended December 31,
		2017		2016		2015
	(Thousands of Dollars)
Long-term incentive plan compensation expense charged to NuStar Energy		$	—	$	490	$	6,397
Expenses resulting from NuStar GP Holdings awards		$	849	$	661	$	239