CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Cash Flows from Operating Activities:
Net income	$ 86,775	$ 55,068	$ 72,208
Adjustments to reconcile net income to net cash provided by operating activities:
Equity in earnings of NuStar Energy L.P.	(51,556)	(56,096)	(79,673)
Distributions of equity in earnings from NuStar Energy L.P.	51,556	56,096	79,673
Gain related to NuStar Energy L.P.’s issuance of common limited partner units	(41,942)	(2,408)	0
(Gain) loss on sale of NuStar Energy L.P. common limited partner units in connection with unit-based compensation	0	(613)	2,333
Unit-based compensation expense	849	661	239
Amortization of deferred debt costs	182	169	155
Expense (benefit) for deferred income tax	1,837	(75)	952
Changes in current assets and liabilities (Note 8)	92	(3,336)	296
(Increase) decrease in long-term receivable from related party	0	(898)	363
Increase (decrease) in long-term liabilities	0	1,183	(647)
Net cash provided by operating activities	47,793	49,751	75,899
Cash Flows from Investing Activities:
Distributions in excess of equity in earnings from NuStar Energy L.P.	47,754	39,809	16,357
Investment in NuStar Energy L.P.	(13,738)	(842)	(7,444)
Proceeds from sale of NuStar Energy L.P. common units in connection with unit-based compensation	0	1,319	5,935
Net cash provided by investing activities	34,016	40,286	14,848
Cash Flows from Financing Activities:
Proceeds from short-term debt borrowings	15,500	4,000	0
Repayment of short-term debt	(3,000)	0	0
Distributions to unitholders	(93,634)	(93,590)	(93,567)
Other, net	(460)	(274)	14
Net cash used in financing activities	(81,594)	(89,864)	(93,553)
Net increase (decrease) in cash and cash equivalents	215	173	(2,806)
Cash and cash equivalents as of the beginning of the period	207	34	2,840
Cash and cash equivalents as of the end of the period	$ 422	$ 207	$ 34