A general description of the nature of the existing leasing arrangements of a lessee for all operating leases including, but not limited to: (1) rental escalation clauses; (2) renewal or purchase options; (3) guarantees or indemnities, if any, (4) restrictions imposed by lease arrangements; (5) unusual provisions or conditions; (6) contingent rentals, if any; and (7) lease expiration dates.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 840
-SubTopic 10
-Section 55
-Paragraph 40
-Subparagraph (Note 1)
-URI http://asc.fasb.org/extlink&oid=82846649&loc=d3e38371-112697

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 840
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=84164451&loc=d3e36991-112694

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Describes the terms of a significant arrangement with a supplier (excluding an unconditional purchase obligation) to acquire goods or services over a period of time beyond one year or the normal operating cycle, if longer, which may include identification of the goods or services to be purchased, pricing, effects on pricing of failing to reach minimum quantities required to be purchased, cancellation rights, and termination provisions.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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- Definition

Rental expense for the reporting period incurred under operating leases, including minimum and any contingent rent expense, net of related sublease income.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 840
-SubTopic 20
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=77902758&loc=d3e41499-112717

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COMMITMENTS AND CONTINGENCIES Narrative 2 - Lessee Commitments (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Major Operating Leases
Rent expense for operating leases (lessee)	$ 36.2	$ 37.0	$ 39.7
Description of purchase obligations	Our purchase obligations primarily consist of an eleven-year chemical supply agreement related to our pipelines.
St Eustatius Tugs and Barges [Member]
Major Operating Leases
Description of leasing arrangements for operating leases (lessee)	a ten-year lease for tugs and barges utilized at our St. Eustatius facility for bunker fuel sales, with two five-year renewal options
Land Leases [Member]
Major Operating Leases
Description of leasing arrangements for operating leases (lessee)	land leases at various terminal facilities, with original terms ranging from 10 to 100 years.