Leases (Schedule Of Future Minimum Lease Payments Under Operating Leases) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014
Operating Leased Assets [Line Items]
2015	$ 111,137
2016	50,879
2017	30,980
2018	15,910
2019	7,090
Thereafter	17,597
Future minimum lease payments under operating leases	233,593
Marine Equipment [Member] \| Tank Barges [Member]
Operating Leased Assets [Line Items]
2015	13,930
2016	8,872
2017	7,473
2018	6,594
2019	3,567
Thereafter	2,239
Future minimum lease payments under operating leases	42,675
Marine Equipment [Member] \| Towing Vessels [Member]
Operating Leased Assets [Line Items]
2015	89,491
2016	35,656
2017	17,746
2018	4,212
2019	0
Thereafter	0
Future minimum lease payments under operating leases	147,105
Land Buildings and Equipment [Member]
Operating Leased Assets [Line Items]
2015	7,716
2016	6,351
2017	5,761
2018	5,104
2019	3,523
Thereafter	15,358
Future minimum lease payments under operating leases	$ 43,813

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Amount of required minimum rental payments for leases having an initial or remaining non-cancelable letter-terms in excess of one year.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 840

-SubTopic 10

-Section 55

-Paragraph 40

-Subparagraph (Note 3)

-URI http://asc.fasb.org/extlink&oid=6584154&loc=d3e38371-112697

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 840

-SubTopic 20

-Section 50

-Paragraph 2

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=6453985&loc=d3e41502-112717

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Amount of required minimum rental payments maturing in the next fiscal year following the latest fiscal year for operating leases having an initial or remaining non-cancelable letter-terms in excess of one year.

+ References

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Amount of required minimum rental payments maturing in the fifth fiscal year following the latest fiscal year for operating leases having an initial or remaining non-cancelable letter-terms in excess of one year.

+ References

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Amount of required minimum rental payments maturing in the forth fiscal year following the latest fiscal year for operating leases having an initial or remaining non-cancelable letter-terms in excess of one year.

+ References

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Amount of required minimum rental payments maturing in the third fiscal year following the latest fiscal year for operating leases having an initial or remaining non-cancelable letter-terms in excess of one year.

+ References

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Amount of required minimum rental payments maturing in the second fiscal year following the latest fiscal year for operating leases having an initial or remaining non-cancelable letter-terms in excess of one year.

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Amount of required minimum rental payments maturing after the fifth fiscal year following the latest fiscal year for operating leases having an initial or remaining non-cancelable letter-terms in excess of one year.

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