Leases (Schedule Of Future Minimum Lease Payments Under Operating Leases) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013
Operating Leased Assets [Line Items]
2014	$ 101,135
2015	69,750
2016	31,004
2017	20,061
2018	14,345
Thereafter	29,309
Future minimum lease payments under operating leases	265,604
Marine Equipment [Member] | Tank Barges [Member]
Operating Leased Assets [Line Items]
2014	18,365
2015	16,267
2016	12,112
2017	10,773
2018	9,654
Thereafter	10,426
Future minimum lease payments under operating leases	77,597
Marine Equipment [Member] | Towing Vessels [Member]
Operating Leased Assets [Line Items]
2014	75,175
2015	46,828
2016	12,764
2017	4,027
2018	0
Thereafter	0
Future minimum lease payments under operating leases	138,794
Land Buildings and Equipment [Member]
Operating Leased Assets [Line Items]
2014	7,595
2015	6,655
2016	6,128
2017	5,261
2018	4,691
Thereafter	18,883
Future minimum lease payments under operating leases	$ 49,213