Revenue Recognition (Disaggregated Revenue) (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2018 USD ($)
Disaggregation of Revenue [Line Items]
Total revenues	$ 725,808
Transferred over time | Fee-based revenues
Disaggregation of Revenue [Line Items]
Total revenues	152,527
Transferred over time | Refinery Services
Disaggregation of Revenue [Line Items]
Total revenues	21,945
Transferred at point in time | Product Sales
Disaggregation of Revenue [Line Items]
Total revenues	551,336
Onshore Facilities & Transportation
Disaggregation of Revenue [Line Items]
Total revenues	317,709
Onshore Facilities & Transportation | Transferred over time | Fee-based revenues
Disaggregation of Revenue [Line Items]
Total revenues	30,338
Onshore Facilities & Transportation | Transferred over time | Refinery Services
Disaggregation of Revenue [Line Items]
Total revenues	0
Onshore Facilities & Transportation | Transferred at point in time | Product Sales
Disaggregation of Revenue [Line Items]
Total revenues	287,371
Sodium Minerals & Sulfur Services
Disaggregation of Revenue [Line Items]
Total revenues	285,910
Sodium Minerals & Sulfur Services | Transferred over time | Fee-based revenues
Disaggregation of Revenue [Line Items]
Total revenues	0
Sodium Minerals & Sulfur Services | Transferred over time | Refinery Services
Disaggregation of Revenue [Line Items]
Total revenues	21,945
Sodium Minerals & Sulfur Services | Transferred at point in time | Product Sales
Disaggregation of Revenue [Line Items]
Total revenues	263,965
Offshore Pipeline Transportation
Disaggregation of Revenue [Line Items]
Total revenues	73,260
Offshore Pipeline Transportation | Transferred over time | Fee-based revenues
Disaggregation of Revenue [Line Items]
Total revenues	73,260
Offshore Pipeline Transportation | Transferred over time | Refinery Services
Disaggregation of Revenue [Line Items]
Total revenues	0
Offshore Pipeline Transportation | Transferred at point in time | Product Sales
Disaggregation of Revenue [Line Items]
Total revenues	0
Marine Transportation
Disaggregation of Revenue [Line Items]
Total revenues	48,929
Marine Transportation | Transferred over time | Fee-based revenues
Disaggregation of Revenue [Line Items]
Total revenues	48,929
Marine Transportation | Transferred over time | Refinery Services
Disaggregation of Revenue [Line Items]
Total revenues	0
Marine Transportation | Transferred at point in time | Product Sales
Disaggregation of Revenue [Line Items]
Total revenues	$ 0