UNIT-BASED COMPENSATION Narrative 2 (Details) - The 2006 LTIP [Member]	12 Months Ended
Dec. 31, 2017
Restricted units, employees [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unit-based compensation, vesting period	5 years
Restricted units, non-employee directors [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unit-based compensation, vesting period	3 years

Period which an employee's right to exercise an award is no longer contingent on satisfaction of either a service condition, market condition or a performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration