Net Income per BUC Narrative Tagging (Details) - shares	3 Months Ended
Mar. 31, 2017	Mar. 31, 2016
Earnings Per Share Diluted [Line Items]
Weighted average number of units outstanding, diluted	60,037,687	60,252,928
Restricted Unit Awards [Member]
Earnings Per Share Diluted [Line Items]
Weighted average number of units outstanding, diluted	0	0

Weighted average number of limited partnership units outstanding determined by relating the portion of time within a reporting period that limited partnership units have been outstanding to the total time in that period. Used in the calculation of diluted net income or loss per limited partnership unit.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 5
-Subparagraph (SAB Topic 4.F)
-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187171-122770

Name:	us-gaap_WeightedAverageLimitedPartnershipUnitsOutstandingDiluted
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration