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Description of Business and Presentation of Financial Statements (Details) - USD ($)
$ / shares in Units, $ in Thousands
1 Months Ended 3 Months Ended
Oct. 31, 2017
Mar. 31, 2018
Mar. 31, 2017
Dec. 31, 2017
Other Ownership Interests [Line Items]        
Ownership percentage, controlling interest   57.00%    
General partner interest 2.00%      
Common Unit, Issued 37,250,000      
Limited partner distribution $ 2,500 $ 66,551 $ 39,632  
Partners' Capital Account, Units, Sold in Private Placement   3,700,000    
Sale of Stock, Price Per Share   $ 29.73    
Proceeds from Issuance of Private Placement   $ 110,000    
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification   $ 1,320    
SLC Pipeline [Member]        
Other Ownership Interests [Line Items]        
Equity Method Investment, Ownership Percentage       75.00%
UNEV Pipeline [Member]        
Other Ownership Interests [Line Items]        
Equity Method Investment, Ownership Percentage   75.00%    
Frontier Pipeline [Member]        
Other Ownership Interests [Line Items]        
Equity Method Investment, Ownership Percentage   50.00%   50.00%