Business Segment Information (Schedule of Total Assets By Reportable Segment) (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Segment Reporting Information [Line Items]
TOTAL ASSETS	$ 5,702,592	$ 5,459,599	$ 3,210,624
Offshore Pipeline Transportation [Member]
Segment Reporting Information [Line Items]
TOTAL ASSETS	2,575,335	2,623,478	645,668
Refinery Services [Member]
Segment Reporting Information [Line Items]
TOTAL ASSETS	395,043	394,626	403,703
Marine Transportation [Member]
Segment Reporting Information [Line Items]
TOTAL ASSETS	813,722	777,952	745,128
Supply And Logistics [Member]
Segment Reporting Information [Line Items]
TOTAL ASSETS	1,875,403	1,615,335	1,367,201
Other Assets [Member]
Segment Reporting Information [Line Items]
TOTAL ASSETS	$ 43,089	$ 48,208	$ 48,924