Net Income Per Limited Partner Unit (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Net income per limited partner unit
Net income	$ 109,466	$ 87,175	$ 217,571	$ 162,267
Net income attributable to incentive distribution rights	(33,145)	(15,328)	(61,598)	(26,881)
Limited partners' interest in net income	$ 76,321	$ 71,847	$ 155,973	$ 135,386
Net income per limited partner unit - basic and diluted	$ 0.41	$ 0.39	$ 0.83	$ 0.73
Weighted average limited partner units outstanding - basic	187,018,000	186,065,000	186,976,000	184,558,000
Weighted average limited partner units outstanding - diluted	187,318,000	186,533,000	187,242,000	185,002,000
Phantom share units
Net income per limited partner unit
Weighted average limited partner units outstanding - diluted	300,243		266,300
Restricted and phantom unit award
Net income per limited partner unit
Weighted average limited partner units outstanding - diluted			187,242,417
Weighted average units outstanding:
Antidilutive securities excluded from computation of earnings per share			0
Common units
Net income per limited partner unit
Weighted average limited partner units outstanding - diluted	187,318,269

Aggregate amount of net income allocated to general partners subsequent to IPO.

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Aggregate amount of net income allocated to limited partners subsequent to IPO.

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Weighted average number of limited partnership units outstanding.

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Securities (including those issuable pursuant to contingent stock agreements) that could potentially dilute basic earnings per share (EPS) or earnings per unit (EPU) in the future that were not included in the computation of diluted EPS or EPU because to do so would increase EPS or EPU amounts or decrease loss per share or unit amounts for the period presented.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 260
-SubTopic 10
-Section 50
-Paragraph 1
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Amount, before tax, of income (loss) attributable to parent. Includes, but is not limited to, income (loss) from continuing operations, discontinued operations and equity method investments.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.20)
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The amount of net income or loss for the period per each limited partnership and general partnership unit in instances when basic and diluted earnings per unit are the same amount and aggregated on the face of the financial statements. Basic earnings per unit is the amount of net income or loss for the period per unit outstanding during the reporting period. Diluted earnings per unit includes the amount of net income or loss for the period available to each limited and general partnership unit outstanding during the reporting period and to each unit that would have been outstanding assuming the issuance of units for all dilutive potential units outstanding during the reporting period.

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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.

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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)
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