DEBT	3 Months Ended
Mar. 31, 2018
Debt Disclosure [Abstract]
DEBT	DEBT Revolving Credit Agreement On March 28, 2018, NuStar Logistics amended its $1.75 billion revolving credit agreement (the Revolving Credit Agreement), to increase the maximum allowed consolidated debt coverage ratio (as defined in the Revolving Credit Agreement) to 5.25-to-1.00 for the rolling periods ending June 30, 2018 through December 31, 2018. Subsequently, the maximum allowed consolidated debt coverage ratio may not exceed 5.00-to-1.00 for any rolling periods ending on or after March 31, 2019. The Revolving Credit Agreement was also amended, to, among other things, change the definition of Change in Control in the Revolving Credit Agreement such that the proposed Merger discussed in Note 2 will not constitute a Change in Control for purposes of the Revolving Credit Agreement. The requirement not to exceed a maximum consolidated debt coverage ratio may limit the amount we can borrow under the Revolving Credit Agreement to an amount less than the total amount available for borrowing. As of March 31, 2018, letters of credit issued under the Revolving Credit Agreement totaled $3.7 million, and we had $804.9 million available for borrowing. As of March 31, 2018, our consolidated debt coverage ratio could not exceed 5.50-to-1.00. We believe that we are in compliance with the covenants in the Revolving Credit Agreement as of March 31, 2018. During the three months ended March 31, 2018, the balance under the Revolving Credit Agreement increased by $48.1 million. The Revolving Credit Agreement bears interest, at our option, based on an alternative base rate, a LIBOR-based rate or a EURIBOR-based rate. The interest rate on the Revolving Credit Agreement is subject to adjustment if our debt rating is downgraded (or upgraded) by certain credit rating agencies. In February 2018, Moody’s Investor Service Inc. (Moody’s) lowered our credit rating from Ba1 to Ba2. This rating downgrade caused the interest rate on our Revolving Credit Agreement to increase by 0.25% effective February 2018. As of March 31, 2018, our weighted-average interest rate related to borrowings under the Revolving Credit Agreement was 3.6%, and we had $941.4 million outstanding. NuStar Logistics Senior Notes The credit rating downgrade by Moody’s in February 2018 increased the interest rate on our $350.0 million of 7.65% senior notes by 0.25%, resulting in an interest rate of 8.65% applicable to the interest payment due April 15, 2018. We repaid our $350.0 million of 7.65% senior notes due April 15, 2018 with borrowings under our Revolving Credit Agreement at maturity. NuStar Logistics Subordinated Notes Effective January 15, 2018, the interest rate on NuStar Logistics’ $402.5 million of fixed-to-floating rate subordinated notes due January 15, 2043 switched from a fixed annual rate of 7.625%, payable quarterly in arrears, to an annual rate equal to the sum of the three-month LIBOR rate for the related quarterly interest period, plus 6.734% payable quarterly, commencing with the interest payment due April 15, 2018. As of March 31, 2018, the floating interest rate was 8.5%. Receivables Financing Agreement NuStar Energy and NuStar Finance LLC (NuStar Finance), a special purpose entity and wholly owned subsidiary of NuStar Energy, are parties to a $125.0 million receivables financing agreement with third-party lenders (the Receivables Financing Agreement) and agreements with certain of NuStar Energy’s wholly owned subsidiaries (collectively with the Receivables Financing Agreement, the Securitization Program). NuStar Finance’s sole activity consists of purchasing receivables from NuStar Energy’s wholly owned subsidiaries that participate in the Securitization Program and providing these receivables as collateral for NuStar Finance’s revolving borrowings under the Securitization Program. NuStar Finance is a separate legal entity and the assets of NuStar Finance, including these accounts receivable, are not available to satisfy the claims of creditors of NuStar Energy, its subsidiaries selling receivables under the Securitization Program or their affiliates. The amount available for borrowing is based on the availability of eligible receivables and other customary factors and conditions. The amendment to the Revolving Credit Agreement also limits the amount of borrowings under the Receivables Financing Agreement to $125.0 million. Borrowings by NuStar Finance under the Receivables Financing Agreement bear interest at the applicable bank rate, as defined under the Receivables Financing Agreement. The weighted average interest rate related to outstanding borrowings under the Securitization Program as of March 31, 2018 was 2.8%. As of March 31, 2018, $91.8 million of our accounts receivable, net of allowance for doubtful accounts, are included in the Securitization Program. The amount of borrowings outstanding under the Receivables Financing Agreement totaled $57.8 million as of March 31, 2018, which is included in “Long-term debt” on the consolidated balance sheet. On March 28, 2018, the Receivables Financing Agreement was amended to change the definition of Change in Control in the Receivables Financing Agreement such that the proposed Merger discussed in Note 2 will not be a Change in Control for purposes of the Receivables Financing Agreement.

DEBT

Revolving Credit Agreement

On March 28, 2018, NuStar Logistics amended its $1.75 billion revolving credit agreement (the Revolving Credit Agreement), to increase the maximum allowed consolidated debt coverage ratio (as defined in the Revolving Credit Agreement) to 5.25-to-1.00 for the rolling periods ending June 30, 2018 through December 31, 2018. Subsequently, the maximum allowed consolidated debt coverage ratio may not exceed 5.00-to-1.00 for any rolling periods ending on or after March 31, 2019. The Revolving Credit Agreement was also amended, to, among other things, change the definition of Change in Control in the Revolving Credit Agreement such that the proposed Merger discussed in Note 2 will not constitute a Change in Control for purposes of the Revolving Credit Agreement.

The requirement not to exceed a maximum consolidated debt coverage ratio may limit the amount we can borrow under the Revolving Credit Agreement to an amount less than the total amount available for borrowing. As of March 31, 2018, letters of credit issued under the Revolving Credit Agreement totaled $3.7 million, and we had $804.9 million available for borrowing. As of March 31, 2018, our consolidated debt coverage ratio could not exceed 5.50-to-1.00. We believe that we are in compliance with the covenants in the Revolving Credit Agreement as of March 31, 2018.

During the three months ended March 31, 2018, the balance under the Revolving Credit Agreement increased by $48.1 million. The Revolving Credit Agreement bears interest, at our option, based on an alternative base rate, a LIBOR-based rate or a EURIBOR-based rate. The interest rate on the Revolving Credit Agreement is subject to adjustment if our debt rating is downgraded (or upgraded) by certain credit rating agencies. In February 2018, Moody’s Investor Service Inc. (Moody’s) lowered our credit rating from Ba1 to Ba2. This rating downgrade caused the interest rate on our Revolving Credit Agreement to increase by 0.25% effective February 2018. As of March 31, 2018, our weighted-average interest rate related to borrowings under the Revolving Credit Agreement was 3.6%, and we had $941.4 million outstanding.

NuStar Logistics Senior Notes

The credit rating downgrade by Moody’s in February 2018 increased the interest rate on our $350.0 million of 7.65% senior notes by 0.25%, resulting in an interest rate of 8.65% applicable to the interest payment due April 15, 2018. We repaid our $350.0 million of 7.65% senior notes due April 15, 2018 with borrowings under our Revolving Credit Agreement at maturity.

NuStar Logistics Subordinated Notes

Effective January 15, 2018, the interest rate on NuStar Logistics’ $402.5 million of fixed-to-floating rate subordinated notes due January 15, 2043 switched from a fixed annual rate of 7.625%, payable quarterly in arrears, to an annual rate equal to the sum of the three-month LIBOR rate for the related quarterly interest period, plus 6.734% payable quarterly, commencing with the interest payment due April 15, 2018. As of March 31, 2018, the floating interest rate was 8.5%.

Receivables Financing Agreement

NuStar Energy and NuStar Finance LLC (NuStar Finance), a special purpose entity and wholly owned subsidiary of NuStar Energy, are parties to a $125.0 million receivables financing agreement with third-party lenders (the Receivables Financing Agreement) and agreements with certain of NuStar Energy’s wholly owned subsidiaries (collectively with the Receivables Financing Agreement, the Securitization Program). NuStar Finance’s sole activity consists of purchasing receivables from NuStar Energy’s wholly owned subsidiaries that participate in the Securitization Program and providing these receivables as collateral for NuStar Finance’s revolving borrowings under the Securitization Program. NuStar Finance is a separate legal entity and the assets of NuStar Finance, including these accounts receivable, are not available to satisfy the claims of creditors of NuStar Energy, its subsidiaries selling receivables under the Securitization Program or their affiliates. The amount available for borrowing is based on the availability of eligible receivables and other customary factors and conditions. The amendment to the Revolving Credit Agreement also limits the amount of borrowings under the Receivables Financing Agreement to $125.0 million.

Borrowings by NuStar Finance under the Receivables Financing Agreement bear interest at the applicable bank rate, as defined under the Receivables Financing Agreement. The weighted average interest rate related to outstanding borrowings under the Securitization Program as of March 31, 2018 was 2.8%. As of March 31, 2018, $91.8 million of our accounts receivable, net of allowance for doubtful accounts, are included in the Securitization Program. The amount of borrowings outstanding under the Receivables Financing Agreement totaled $57.8 million as of March 31, 2018, which is included in “Long-term debt” on the consolidated balance sheet. On March 28, 2018, the Receivables Financing Agreement was amended to change the definition of Change in Control in the Receivables Financing Agreement such that the proposed Merger discussed in Note 2 will not be a Change in Control for purposes of the Receivables Financing Agreement.