Business Segment Information (Schedule Of Total Assets By Reportable Segment) (Details) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Segment Reporting Information [Line Items]
Total consolidated assets	$ 3,404,281	$ 3,230,374
Pipeline Transportation [Member]
Segment Reporting Information [Line Items]
Total consolidated assets	516,365	460,012
Offshore Pipeline Transportation [Member]
Segment Reporting Information [Line Items]
Total consolidated assets	631,998	645,668
Refinery Services [Member]
Segment Reporting Information [Line Items]
Total consolidated assets	394,794	403,703
Marine Transportation [Member]
Segment Reporting Information [Line Items]
Total consolidated assets	754,515	745,128
Supply And Logistics [Member]
Segment Reporting Information [Line Items]
Total consolidated assets	1,042,620	907,189
Other Assets [Member]
Segment Reporting Information [Line Items]
Total consolidated assets	$ 63,989	$ 68,674