v3.10.0.1

SEGMENT INFORMATION (Tables) | 9 Months Ended
--- | ---
Sep. 30, 2018
Segment Reporting [Abstract] |
Schedule of Segment Reporting Information, by Segment [Table Text Block] | Results of operations for the reportable segments were as follows:
| Three Months Ended September 30, |  | Nine Months Ended September 30,
| 2018 |  | 2017 |  | 2018 |  | 2017
| (Thousands of Dollars)
Revenues: |  |  |  |  |  |  |
Pipeline | $ | 162,843 |  |  | $ | 137,426 |  |  | $ | 449,909 |  |  | $ | 385,406 |
Storage: |  |  |  |  |  |  |
Third parties | 152,411 |  |  | 155,677 |  |  | 461,109 |  |  | 453,995 |
Intersegment | 1,719 |  |  | 2,394 |  |  | 5,799 |  |  | 10,066 |
Total storage | 154,130 |  |  | 158,071 |  |  | 466,908 |  |  | 464,061 |
Fuels marketing | 175,109 |  |  | 147,463 |  |  | 541,430 |  |  | 524,083 |
Consolidation and intersegment eliminations | (1,719 | ) |  | (2,394 | ) |  | (5,799 | ) |  | (10,066 | )
Total revenues | $ | 490,363 |  |  | $ | 440,566 |  |  | $ | 1,452,448 |  |  | $ | 1,363,484 |
Operating income: |  |  |  |  |  |  |
Pipeline | $ | 77,021 |  |  | $ | 61,119 |  |  | $ | 197,794 |  |  | $ | 179,015 |
Storage | 46,459 |  |  | 59,323 |  |  | 146,904 |  |  | 169,131 |
Fuels marketing | 1,890 |  |  | (1,532 | ) |  | 11,114 |  |  | 3,897 |
Consolidation and intersegment eliminations | — |  |  | (1 | ) |  | — |  |  | — |
Total segment operating income | 125,370 |  |  | 118,909 |  |  | 355,812 |  |  | 352,043 |
General and administrative expenses | 27,817 |  |  | 25,003 |  |  | 75,572 |  |  | 83,202 |
Other depreciation and amortization expense | 2,276 |  |  | 2,189 |  |  | 6,645 |  |  | 6,581 |
Total operating income | $ | 95,277 |  |  | $ | 91,717 |  |  | $ | 273,595 |  |  | $ | 262,260 |
Reconciliation of Assets from Segment to Consolidated [Table Text Block] | Total assets by reportable segment were as follows:
| September 30, 2018 |  | December 31, 2017
| (Thousands of Dollars)
Pipeline | $ | 3,606,413 |  |  | $ | 3,492,417 |
Storage | 2,787,886 |  |  | 2,735,563 |
Fuels marketing | 132,497 |  |  | 118,746 |
Total segment assets | 6,526,796 |  |  | 6,346,726 |
Other partnership assets | 194,162 |  |  | 188,507 |
Total consolidated assets | $ | 6,720,958 |  |  | $ | 6,535,233 |

X
- Definition Tabular disclosure of all significant reconciling items in the reconciliation of total assets from reportable segments to the entity's consolidated assets. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 30 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=115929826&loc=d3e8906-108599 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 31 -URI http://asc.fasb.org/extlink&oid=115929826&loc=d3e8924-108599 + Details
Name: | us-gaap_ReconciliationOfAssetsFromSegmentToConsolidatedTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of the profit or loss and total assets for each reportable segment. An entity discloses certain information on each reportable segment if the amounts (a) are included in the measure of segment profit or loss reviewed by the chief operating decision maker or (b) are otherwise regularly provided to the chief operating decision maker, even if not included in that measure of segment profit or loss. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 22 -URI http://asc.fasb.org/extlink&oid=115929826&loc=d3e8736-108599 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 25 -URI http://asc.fasb.org/extlink&oid=115929826&loc=d3e8813-108599 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=108376223&loc=d3e13816-109267 Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 21 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=115929826&loc=d3e8721-108599 Reference 5: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 30 -URI http://asc.fasb.org/extlink&oid=115929826&loc=d3e8906-108599 + Details
Name: | us-gaap_ScheduleOfSegmentReportingInformationBySegmentTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_SegmentReportingAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration