Business Segment Information (Schedule Of Total Assets By Reportable Segment) (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Segment Reporting Information [Line Items]
Total consolidated assets	$ 5,655,484	$ 5,459,599
Onshore pipeline transportation
Segment Reporting Information [Line Items]
Total consolidated assets	706,589	614,484
Offshore pipeline transportation
Segment Reporting Information [Line Items]
Total consolidated assets	2,595,408	2,623,478
Refinery services
Segment Reporting Information [Line Items]
Total consolidated assets	390,169	394,626
Marine transportation
Segment Reporting Information [Line Items]
Total consolidated assets	813,282	777,952
Supply and logistics
Segment Reporting Information [Line Items]
Total consolidated assets	1,107,798	1,000,851
Other assets
Segment Reporting Information [Line Items]
Total consolidated assets	$ 42,238	$ 48,208