Net Income per Limited Partner Unit - Basic and Diluted Table (Details) - shares shares in Thousands	3 Months Ended
Mar. 31, 2018	Mar. 31, 2017
Common Units
Weighted average number of units outstanding
Weighted-average common units outstanding - basic	14,438	14,380
Effect of nonvested phantom units		848
Weighted-average common units outstanding —diluted	14,438	15,228
Subordinated Units-Sponsor
Weighted average number of units outstanding
Weighted-average common units outstanding - basic	11,905	11,905
Weighted-average common units outstanding —diluted	11,905	11,905

Additional shares included in the calculation of diluted EPS as a result of the potentially dilutive effect of share based payment arrangements using the treasury stock method.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 260
-SubTopic 10
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6371337&loc=d3e3550-109257

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-Name Accounting Standards Codification
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The average number of shares or units issued and outstanding that are used in calculating diluted EPS or earnings per unit (EPU), determined based on the timing of issuance of shares or units in the period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Number of [basic] shares or units, after adjustment for contingently issuable shares or units and other shares or units not deemed outstanding, determined by relating the portion of time within a reporting period that common shares or units have been outstanding to the total time in that period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
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