Organization, Description of Business and Basis of Presentation (Narrative) (Details) bbl in Millions, $ in Millions	Jan. 01, 2019 USD ($)	Mar. 31, 2019 Terminal bbl mi
Refined Products Segment [Member]
Organization and Description of Business [Line Items]
Number of Pipeline Terminals | Terminal		53
Number of Independent Terminals | Terminal		25
Refined Products Segment [Member] | Refined Products Transportation Services [Member]
Organization and Description of Business [Line Items]
Pipeline Length | mi		9,700
Refined Products Segment [Member] | Ammonia Transportation Services [Member]
Organization and Description of Business [Line Items]
Pipeline Length | mi		1,100
Crude Oil Pipeline and Terminals Segment [Member]
Organization and Description of Business [Line Items]
Pipeline Length | mi		2,200
Storage Capacity		33
Contracted Storage		21
Pipeline, Length - Wholly Owned | mi		1,000
Storage Capacity - Wholly Owned		28
Contracted Storage - Wholly Owned		19
Marine Storage Segment [Member]
Organization and Description of Business [Line Items]
Number of Independent Terminals | Terminal		6
Storage Capacity		27
Storage Capacity - Wholly Owned		25
Number of Independent Terminals - Wholly Owned | Terminal		5
Accounting Standards Update 2016-02 [Member] | Assets, Total [Member]
Organization and Description of Business [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification | $	$ 172
Accounting Standards Update 2016-02 [Member] | Liabilities, Total [Member]
Organization and Description of Business [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification | $	$ 172