| Condensed Consolidating Balance Sheets [Text Block] |
Condensed Consolidating Balance Sheets March 31, 2018 (Thousands of Dollars) | | | | | | | | | | | | | | | | | | | | | | | | | | NuStar Energy | | NuStar Logistics | | NuPOP | | Non-Guarantor Subsidiaries | | Eliminations | | Consolidated | Assets | | | | | | | | | | | | Cash and cash equivalents | $ | 858 |
| | $ | 26 |
| | $ | — |
| | $ | 14,244 |
| | $ | — |
| | $ | 15,128 |
| Receivables, net | — |
| | 623 |
| | — |
| | 156,718 |
| | — |
| | 157,341 |
| Inventories | — |
| | 1,844 |
| | 11,039 |
| | 16,666 |
| | — |
| | 29,549 |
| Other current assets | 139 |
| | 13,905 |
| | 3,538 |
| | 8,397 |
| | — |
| | 25,979 |
| Intercompany receivable | — |
| | 3,132,310 |
| | — |
| | — |
| | (3,132,310 | ) | | — |
| Total current assets | 997 |
| | 3,148,708 |
| | 14,577 |
| | 196,025 |
| | (3,132,310 | ) | | 227,997 |
| Property, plant and equipment, net | — |
| | 1,874,347 |
| | 585,056 |
| | 1,927,821 |
| | — |
| | 4,387,224 |
| Intangible assets, net | — |
| | 56,174 |
| | — |
| | 715,449 |
| | — |
| | 771,623 |
| Goodwill | — |
| | 149,453 |
| | 170,652 |
| | 774,556 |
| | — |
| | 1,094,661 |
| Investment in wholly owned subsidiaries | 2,881,187 |
| | 19,795 |
| | 1,413,835 |
| | 851,975 |
| | (5,166,792 | ) | | — |
| Other long-term assets, net | 303 |
| | 70,343 |
| | 27,204 |
| | 7,358 |
| | — |
| | 105,208 |
| Total assets | $ | 2,882,487 |
| | $ | 5,318,820 |
| | $ | 2,211,324 |
| | $ | 4,473,184 |
| | $ | (8,299,102 | ) | | $ | 6,586,713 |
| Liabilities and Partners’ Equity | | | | | | | | | | | | Accounts payable | $ | 3,309 |
| | $ | 19,472 |
| | $ | 5,232 |
| | $ | 94,027 |
| | $ | — |
| | $ | 122,040 |
| Short-term debt | — |
| | 70,000 |
| | — |
| | — |
| | — |
| | 70,000 |
| Current portion of long-term debt | — |
| | 349,973 |
| | — |
| | — |
| | — |
| | 349,973 |
| Accrued interest payable | — |
| | 43,921 |
| | — |
| | 53 |
| | — |
| | 43,974 |
| Accrued liabilities | 655 |
| | 11,579 |
| | 8,214 |
| | 27,072 |
| | — |
| | 47,520 |
| Taxes other than income tax | 206 |
| | 3,906 |
| | 5,246 |
| | 3,393 |
| | — |
| | 12,751 |
| Income tax payable | — |
| | 902 |
| | 4 |
| | 5,472 |
| | — |
| | 6,378 |
| Intercompany payable | 322,257 |
| | — |
| | 1,326,659 |
| | 1,483,394 |
| | (3,132,310 | ) | | — |
| Total current liabilities | 326,427 |
| | 499,753 |
| | 1,345,355 |
| | 1,613,411 |
| | (3,132,310 | ) | | 652,636 |
| Long-term debt, less current portion | — |
| | 3,248,763 |
| | — |
| | 57,330 |
| | — |
| | 3,306,093 |
| Deferred income tax liability | — |
| | 1,262 |
| | 12 |
| | 21,758 |
| | — |
| | 23,032 |
| Other long-term liabilities | — |
| | 43,854 |
| | 14,191 |
| | 54,850 |
| | — |
| | 112,895 |
| Total partners’ equity | 2,556,060 |
| | 1,525,188 |
| | 851,766 |
| | 2,725,835 |
| | (5,166,792 | ) | | 2,492,057 |
| Total liabilities and partners’ equity | $ | 2,882,487 |
| | $ | 5,318,820 |
| | $ | 2,211,324 |
| | $ | 4,473,184 |
| | $ | (8,299,102 | ) | | $ | 6,586,713 |
|
Condensed Consolidating Balance Sheets December 31, 2017 (Thousands of Dollars) | | | | | | | | | | | | | | | | | | | | | | | | | | NuStar Energy | | NuStar Logistics | | NuPOP | | Non-Guarantor Subsidiaries | | Eliminations | | Consolidated | Assets | | | | | | | | | | | | Cash and cash equivalents | $ | 885 |
| | $ | 29 |
| | $ | — |
| | $ | 23,378 |
| | $ | — |
| | $ | 24,292 |
| Receivables, net | — |
| | 280 |
| | — |
| | 176,495 |
| | — |
| | 176,775 |
| Inventories | — |
| | 1,686 |
| | 8,611 |
| | 16,560 |
| | — |
| | 26,857 |
| Other current assets | 61 |
| | 11,412 |
| | 4,191 |
| | 6,844 |
| | — |
| | 22,508 |
| Intercompany receivable | — |
| | 3,112,164 |
| | — |
| | — |
| | (3,112,164 | ) | | — |
| Total current assets | 946 |
| | 3,125,571 |
| | 12,802 |
| | 223,277 |
| | (3,112,164 | ) | | 250,432 |
| Property, plant and equipment, net | — |
| | 1,893,720 |
| | 591,070 |
| | 1,816,143 |
| | — |
| | 4,300,933 |
| Intangible assets, net | — |
| | 58,530 |
| | — |
| | 725,949 |
| | — |
| | 784,479 |
| Goodwill | — |
| | 149,453 |
| | 170,652 |
| | 777,370 |
| | — |
| | 1,097,475 |
| Investment in wholly owned subsidiaries | 2,891,371 |
| | 24,162 |
| | 1,301,717 |
| | 790,882 |
| | (5,008,132 | ) | | — |
| Deferred income tax asset | — |
| | — |
| | — |
| | 233 |
| | — |
| | 233 |
| Other long-term assets, net | 303 |
| | 65,684 |
| | 27,493 |
| | 8,201 |
| | — |
| | 101,681 |
| Total assets | $ | 2,892,620 |
| | $ | 5,317,120 |
| | $ | 2,103,734 |
| | $ | 4,342,055 |
| | $ | (8,120,296 | ) | | $ | 6,535,233 |
| Liabilities and Partners’ Equity | | | | | | | | | | | | Accounts payable | $ | 4,078 |
| | $ | 27,642 |
| | $ | 13,160 |
| | $ | 101,052 |
| | $ | — |
| | $ | 145,932 |
| Short-term debt | — |
| | 35,000 |
| | — |
| | — |
| | — |
| | 35,000 |
| Current portion of long-term debt | — |
| | 349,990 |
| | — |
| | — |
| | — |
| | 349,990 |
| Accrued interest payable | — |
| | 40,402 |
| | — |
| | 47 |
| | — |
| | 40,449 |
| Accrued liabilities | 1,105 |
| | 17,628 |
| | 9,450 |
| | 33,395 |
| | — |
| | 61,578 |
| Taxes other than income tax | 125 |
| | 7,110 |
| | 3,794 |
| | 3,356 |
| | — |
| | 14,385 |
| Income tax payable | — |
| | 732 |
| | 4 |
| | 3,436 |
| | — |
| | 4,172 |
| Intercompany payable | 322,296 |
| | — |
| | 1,277,691 |
| | 1,512,177 |
| | (3,112,164 | ) | | — |
| Total current liabilities | 327,604 |
| | 478,504 |
| | 1,304,099 |
| | 1,653,463 |
| | (3,112,164 | ) | | 651,506 |
| Long-term debt, less current portion | — |
| | 3,201,220 |
| | — |
| | 61,849 |
| | — |
| | 3,263,069 |
| Deferred income tax liability | — |
| | 1,262 |
| | 12 |
| | 20,998 |
| | — |
| | 22,272 |
| Other long-term liabilities | — |
| | 58,806 |
| | 8,861 |
| | 50,630 |
| | — |
| | 118,297 |
| Total partners’ equity | 2,565,016 |
| | 1,577,328 |
| | 790,762 |
| | 2,555,115 |
| | (5,008,132 | ) | | 2,480,089 |
| Total liabilities and partners’ equity | $ | 2,892,620 |
| | $ | 5,317,120 |
| | $ | 2,103,734 |
| | $ | 4,342,055 |
| | $ | (8,120,296 | ) | | $ | 6,535,233 |
|
|
| Condensed Consolidating Statements of Comprehensive Income (Loss) [Table Text Block] |
Condensed Consolidating Statements of Comprehensive Income For the Three Months Ended March 31, 2018 (Thousands of Dollars) | | | | | | | | | | | | | | | | | | | | | | | | | | NuStar Energy | | NuStar Logistics | | NuPOP | | Non-Guarantor Subsidiaries | | Eliminations | | Consolidated | Revenues | $ | — |
| | $ | 119,694 |
| | $ | 56,274 |
| | $ | 300,115 |
| | $ | (202 | ) | | $ | 475,881 |
| Costs and expenses | 612 |
| | 72,416 |
| | 35,181 |
| | 269,394 |
| | (202 | ) | | 377,401 |
| Operating (loss) income | (612 | ) | | 47,278 |
| | 21,093 |
| | 30,721 |
| | — |
| | 98,480 |
| Equity in earnings (loss) of subsidiaries | 126,713 |
| | (2,249 | ) | | 112,003 |
| | 131,639 |
| | (368,106 | ) | | — |
| Interest income (expense), net | 32 |
| | (50,026 | ) | | (1,571 | ) | | 3,793 |
| | — |
| | (47,772 | ) | Other income, net | — |
| | 476 |
| | 115 |
| | 79,161 |
| | — |
| | 79,752 |
| Income (loss) before income tax expense | 126,133 |
| | (4,521 | ) | | 131,640 |
| | 245,314 |
| | (368,106 | ) | | 130,460 |
| Income tax expense | — |
| | 170 |
| | 1 |
| | 4,156 |
| | — |
| | 4,327 |
| Net income (loss) | $ | 126,133 |
| | $ | (4,691 | ) | | $ | 131,639 |
| | $ | 241,158 |
| | $ | (368,106 | ) | | $ | 126,133 |
| | | | | | | | | | | | | Comprehensive income | $ | 126,133 |
| | $ | 14,120 |
| | $ | 131,639 |
| | $ | 243,271 |
| | $ | (368,106 | ) | | $ | 147,057 |
|
Condensed Consolidating Statements of Comprehensive Income For the Three Months Ended March 31, 2017 (Thousands of Dollars) | | | | | | | | | | | | | | | | | | | | | | | | | | NuStar Energy | | NuStar Logistics | | NuPOP | | Non-Guarantor Subsidiaries | | Eliminations | | Consolidated | Revenues | $ | — |
| | $ | 123,629 |
| | $ | 52,241 |
| | $ | 311,847 |
| | $ | (287 | ) | | $ | 487,430 |
| Costs and expenses | 509 |
| | 76,322 |
| | 29,806 |
| | 283,941 |
| | (287 | ) | | 390,291 |
| Operating (loss) income | (509 | ) | | 47,307 |
| | 22,435 |
| | 27,906 |
| | — |
| | 97,139 |
| Equity in earnings of subsidiaries | 58,445 |
| | 1,110 |
| | 26,215 |
| | 47,353 |
| | (133,123 | ) | | — |
| Interest income (expense), net | 4 |
| | (36,914 | ) | | (1,304 | ) | | 1,800 |
| | — |
| | (36,414 | ) | Other income, net | — |
| | 21 |
| | 6 |
| | 113 |
| | — |
| | 140 |
| Income before income tax expense | 57,940 |
| | 11,524 |
| | 47,352 |
| | 77,172 |
| | (133,123 | ) | | 60,865 |
| Income tax expense | — |
| | 331 |
| | 1 |
| | 2,593 |
| | — |
| | 2,925 |
| Net income | $ | 57,940 |
| | $ | 11,193 |
| | $ | 47,351 |
| | $ | 74,579 |
| | $ | (133,123 | ) | | $ | 57,940 |
| | | | | | | | | | | | | Comprehensive income | $ | 57,940 |
| | $ | 13,031 |
| | $ | 47,351 |
| | $ | 76,504 |
| | $ | (133,123 | ) | | $ | 61,703 |
|
|
| Condensed Consolidating Statements of Cash Flows [Text Block] |
Condensed Consolidating Statements of Cash Flows For the Three Months Ended March 31, 2018 (Thousands of Dollars) | | | | | | | | | | | | | | | | | | | | | | | | | | NuStar Energy | | NuStar Logistics | | NuPOP | | Non-Guarantor Subsidiaries | | Eliminations | | Consolidated | Net cash provided by operating activities | $ | 130,847 |
| | $ | 16,855 |
| | $ | 25,112 |
| | $ | 148,287 |
| | $ | (197,937 | ) | | $ | 123,164 |
| Cash flows from investing activities: | | | | | | | | | | | | Capital expenditures | — |
| | (6,815 | ) | | (2,440 | ) | | (128,619 | ) | | — |
| | (137,874 | ) | Change in accounts payable related to capital expenditures | — |
| | (1,946 | ) | | (5,700 | ) | | (4,372 | ) | | — |
| | (12,018 | ) | Proceeds from sale or disposition of assets | — |
| | 6 |
| | 4 |
| | 9 |
| | — |
| | 19 |
| Proceeds from insurance recoveries | — |
| | — |
| | — |
| | 78,419 |
| | — |
| | 78,419 |
| Net cash used in investing activities | — |
| | (8,755 | ) | | (8,136 | ) | | (54,563 | ) | | — |
| | (71,454 | ) | Cash flows from financing activities: | | | | | | | | | | | | Debt borrowings | — |
| | 348,411 |
| | — |
| | 1,300 |
| | — |
| | 349,711 |
| Debt repayments | — |
| | (268,621 | ) | | — |
| | (5,800 | ) | | — |
| | (274,421 | ) | Distributions to preferred unitholders | (16,680 | ) | | (8,341 | ) | | (8,340 | ) | | (8,340 | ) | | 25,021 |
| | (16,680 | ) | Distributions to common unitholders and general partner | (115,272 | ) | | (57,636 | ) | | (57,635 | ) | | (57,645 | ) | | 172,916 |
| | (115,272 | ) | Net intercompany activity | 2,053 |
| | (18,769 | ) | | 48,999 |
| | (32,283 | ) | | — |
| | — |
| Other, net | (975 | ) | | (3,147 | ) | | — |
| | (62 | ) | | — |
| | (4,184 | ) | Net cash used in financing activities | (130,874 | ) | | (8,103 | ) | | (16,976 | ) | | (102,830 | ) | | 197,937 |
| | (60,846 | ) | Effect of foreign exchange rate changes on cash | — |
| | — |
| | — |
| | (28 | ) | | — |
| | (28 | ) | Net decrease in cash and cash equivalents | (27 | ) | | (3 | ) | | — |
| | (9,134 | ) | | — |
| | (9,164 | ) | Cash and cash equivalents as of the beginning of the period | 885 |
| | 29 |
| | — |
| | 23,378 |
| | — |
| | 24,292 |
| Cash and cash equivalents as of the end of the period | $ | 858 |
| | $ | 26 |
| | $ | — |
| | $ | 14,244 |
| | $ | — |
| | $ | 15,128 |
|
Condensed Consolidating Statements of Cash Flows For the Three Months Ended March 31, 2017 (Thousands of Dollars) | | | | | | | | | | | | | | | | | | | | | | | | | | NuStar Energy | | NuStar Logistics | | NuPOP | | Non-Guarantor Subsidiaries | | Eliminations | | Consolidated | Net cash provided by operating activities | $ | 103,517 |
| | $ | 35,964 |
| | $ | 23,855 |
| | $ | 78,004 |
| | $ | (157,360 | ) | | $ | 83,980 |
| Cash flows from investing activities: | | | | | | | | | | | | Capital expenditures | — |
| | (7,671 | ) | | (1,761 | ) | | (36,300 | ) | | — |
| | (45,732 | ) | Change in accounts payable related to capital expenditures | — |
| | (4,908 | ) | | (1,103 | ) | | (809 | ) | | — |
| | (6,820 | ) | Proceeds from sale or disposition of assets | — |
| | 1,833 |
| | 6 |
| | 20 |
| | — |
| | 1,859 |
| Proceeds from Axeon term loan | — |
| | 110,000 |
| | — |
| | — |
| | — |
| | 110,000 |
| Net cash provided by (used in) investing activities | — |
| | 99,254 |
| | (2,858 | ) | | (37,089 | ) | | — |
| | 59,307 |
| Cash flows from financing activities: | | | | | | | | | | | | Debt borrowings | — |
| | 404,166 |
| | — |
| | 6,100 |
| | — |
| | 410,266 |
| Debt repayments | — |
| | (451,694 | ) | | — |
| | (3,500 | ) | | — |
| | (455,194 | ) | Distributions to preferred unitholders | (5,883 | ) | | (2,941 | ) | | (2,941 | ) | | (2,942 | ) | | 8,824 |
| | (5,883 | ) | Distributions to common unitholders and general partner | (99,021 | ) | | (49,511 | ) | | (49,511 | ) | | (49,514 | ) | | 148,536 |
| | (99,021 | ) | Net intercompany activity | 3,196 |
| | (34,952 | ) | | 31,455 |
| | 301 |
| | — |
| | — |
| Other, net | (1,933 | ) | | (285 | ) | | — |
| | — |
| | — |
| | (2,218 | ) | Net cash used in financing activities | (103,641 | ) | | (135,217 | ) | | (20,997 | ) | | (49,555 | ) | | 157,360 |
| | (152,050 | ) | Effect of foreign exchange rate changes on cash | — |
| | — |
| | — |
| | 26 |
| | — |
| | 26 |
| Net (decrease) increase in cash and cash equivalents | (124 | ) | | 1 |
| | — |
| | (8,614 | ) | | — |
| | (8,737 | ) | Cash and cash equivalents as of the beginning of the period | 870 |
| | 5 |
| | — |
| | 35,067 |
| | — |
| | 35,942 |
| Cash and cash equivalents as of the end of the period | $ | 746 |
| | $ | 6 |
| | $ | — |
| | $ | 26,453 |
| | $ | — |
| | $ | 27,205 |
|
|