Nature Of Operations And Accounting Policies (Narrative) (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Nature of Operations and Accounting Policies [Line Items]
Deferred Revenue	$ 6,592,000	$ 6,592,000	$ 9,845,000	$ 20,829,000
Inventory write-down	200,000	200,000	300,000
Depreciation	130,200,000	126,100,000	102,100,000
Capitalized interest	6,400,000	4,300,000	5,800,000
Amortization expense	4,349,000	5,629,000	4,800,000
Asset Impairment Charges	3,000,000	1,200,000	100,000
Amortization expense for deferred financing costs.	1,900,000	500,000	500,000
Offshore Marine Services [Member]
Nature of Operations and Accounting Policies [Line Items]
Deferred Revenue	6,600,000
Percentage of Operating Revenues	45.00%	40.00%	36.00%
Inland River Services [Member]
Nature of Operations and Accounting Policies [Line Items]
Percentage of Operating Revenues	17.00%	17.00%	18.00%
Shipping Services [Member]
Nature of Operations and Accounting Policies [Line Items]
Percentage of Operating Revenues	16.00%	14.00%	16.00%
Ethanol and Industrial Alcohol [Member]
Nature of Operations and Accounting Policies [Line Items]
Percentage of Operating Revenues	16.00%	14.00%
ORM Transaction
Nature of Operations and Accounting Policies [Line Items]
Goodwill, Other Changes		$ 37,100,000