ORGANIZATION AND BASIS OF PRESENTATION Narrative 2 (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended
	Apr. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Mar. 31, 2016	May 04, 2017
Equity Method Investee [Line Items]
General partner interest percentage			2.00%
Proceeds from short-term debt borrowings			$ 1,000	$ 4,000
Subsequent Event [Member] | NuStar Energy Common Unit Issuance [Member]
Equity Method Investee [Line Items]
Limited partner units issued by NuStar Energy		14,375,000
Net proceeds received by NuStar Energy from issuance of units		$ 657,500
Subsequent Event [Member] | NuStar Energy Series B Preferred Unit Issuance [Member]
Equity Method Investee [Line Items]
Limited partner units issued by NuStar Energy		15,400,000
Net proceeds received by NuStar Energy from issuance of units		$ 372,200
NuStar Energy's preferred units distribution rate		7.625%
Subsequent Event [Member] | NuStar Energy Logistics Notes Due 2027 [Member]
Equity Method Investee [Line Items]
NuStar Energy's senior note issuance		$ 550,000
NuStar Energy's senior notes interest rate		5.625%
NuStar Energy's net proceeds from senior note issuance		$ 543,800
Subsequent Event [Member] | Revolving Credit Facility [Member]
Equity Method Investee [Line Items]
Proceeds from short-term debt borrowings	$ 14,000	$ 14,000
Navigator Acquisition [Member] | Subsequent Event [Member]
Equity Method Investee [Line Items]
NuStar Energy's purchase price of acquired entity					$ 1,475,000