Revenue Recognition (Disaggregated Revenue) (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2018
Disaggregation of Revenue [Line Items]
Total revenues	$ 752,388	$ 1,478,196
Transferred over time | Fee-based revenues
Disaggregation of Revenue [Line Items]
Total revenues	161,164	313,691
Transferred over time | Refinery Services
Disaggregation of Revenue [Line Items]
Total revenues	29,730	51,675
Transferred at point in time | Product Sales
Disaggregation of Revenue [Line Items]
Total revenues	561,494	1,112,830
Onshore facilities and transportation
Disaggregation of Revenue [Line Items]
Total revenues	327,353	645,062
Onshore facilities and transportation | Transferred over time | Fee-based revenues
Disaggregation of Revenue [Line Items]
Total revenues	35,010	65,348
Onshore facilities and transportation | Transferred over time | Refinery Services
Disaggregation of Revenue [Line Items]
Total revenues	0	0
Onshore facilities and transportation | Transferred at point in time | Product Sales
Disaggregation of Revenue [Line Items]
Total revenues	292,343	579,714
Sodium Minerals & Sulfur Services
Disaggregation of Revenue [Line Items]
Total revenues	298,881	584,791
Sodium Minerals & Sulfur Services | Transferred over time | Fee-based revenues
Disaggregation of Revenue [Line Items]
Total revenues	0	0
Sodium Minerals & Sulfur Services | Transferred over time | Refinery Services
Disaggregation of Revenue [Line Items]
Total revenues	29,730	51,675
Sodium Minerals & Sulfur Services | Transferred at point in time | Product Sales
Disaggregation of Revenue [Line Items]
Total revenues	269,151	533,116
Offshore Pipeline Transportation
Disaggregation of Revenue [Line Items]
Total revenues	69,969	143,229
Offshore Pipeline Transportation | Transferred over time | Fee-based revenues
Disaggregation of Revenue [Line Items]
Total revenues	69,969	143,229
Offshore Pipeline Transportation | Transferred over time | Refinery Services
Disaggregation of Revenue [Line Items]
Total revenues	0	0
Offshore Pipeline Transportation | Transferred at point in time | Product Sales
Disaggregation of Revenue [Line Items]
Total revenues	0	0
Marine Transportation
Disaggregation of Revenue [Line Items]
Total revenues	56,185	105,114
Marine Transportation | Transferred over time | Fee-based revenues
Disaggregation of Revenue [Line Items]
Total revenues	56,185	105,114
Marine Transportation | Transferred over time | Refinery Services
Disaggregation of Revenue [Line Items]
Total revenues	0	0
Marine Transportation | Transferred at point in time | Product Sales
Disaggregation of Revenue [Line Items]
Total revenues	$ 0	$ 0