Revenue Recognition (Disaggregated Revenue) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Disaggregation of Revenue [Line Items]
Total revenues	$ 634,785	$ 752,388	$ 1,254,794	$ 1,478,196
Fee-based revenues
Disaggregation of Revenue [Line Items]
Total revenues	174,897	161,164	347,876	313,691
Product Sales
Disaggregation of Revenue [Line Items]
Total revenues	437,371	561,494	866,758	1,112,830
Refinery Services
Disaggregation of Revenue [Line Items]
Total revenues	22,517	29,730	40,160	51,675
Onshore Facilities & Transportation
Disaggregation of Revenue [Line Items]
Total revenues	223,046	327,353	432,602	645,062
Onshore Facilities & Transportation | Fee-based revenues
Disaggregation of Revenue [Line Items]
Total revenues	37,764	35,010	75,776	65,348
Onshore Facilities & Transportation | Product Sales
Disaggregation of Revenue [Line Items]
Total revenues	185,282	292,343	356,826	579,714
Onshore Facilities & Transportation | Refinery Services
Disaggregation of Revenue [Line Items]
Total revenues	0	0	0	0
Sodium Minerals & Sulfur Services
Disaggregation of Revenue [Line Items]
Total revenues	274,606	298,881	550,092	584,791
Sodium Minerals & Sulfur Services | Fee-based revenues
Disaggregation of Revenue [Line Items]
Total revenues	0	0	0	0
Sodium Minerals & Sulfur Services | Product Sales
Disaggregation of Revenue [Line Items]
Total revenues	252,089	269,151	509,932	533,116
Sodium Minerals & Sulfur Services | Refinery Services
Disaggregation of Revenue [Line Items]
Total revenues	22,517	29,730	40,160	51,675
Offshore Pipeline Transportation
Disaggregation of Revenue [Line Items]
Total revenues	78,427	69,969	156,744	143,229
Offshore Pipeline Transportation | Fee-based revenues
Disaggregation of Revenue [Line Items]
Total revenues	78,427	69,969	156,744	143,229
Offshore Pipeline Transportation | Product Sales
Disaggregation of Revenue [Line Items]
Total revenues	0	0	0	0
Offshore Pipeline Transportation | Refinery Services
Disaggregation of Revenue [Line Items]
Total revenues	0	0	0	0
Marine Transportation
Disaggregation of Revenue [Line Items]
Total revenues	58,706	56,185	115,356	105,114
Marine Transportation | Fee-based revenues
Disaggregation of Revenue [Line Items]
Total revenues	58,706	56,185	115,356	105,114
Marine Transportation | Product Sales
Disaggregation of Revenue [Line Items]
Total revenues	0	0	0	0
Marine Transportation | Refinery Services
Disaggregation of Revenue [Line Items]
Total revenues	$ 0	$ 0	$ 0	$ 0