SELF-RETENTION INSURANCE (Details) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Property, Plant and Equipment [Line Items]
Minimum self insurance coverage per incident	$ 150,000
Minimum number of days for loss of hire claims	14 days
Liabilities for self insurance exposure and for claims	4,357,000	1,952,000
Minimum [Member]
Property, Plant and Equipment [Line Items]
Third party insurance coverage per incident	100,000
Maximum [Member]
Property, Plant and Equipment [Line Items]
Third party insurance coverage per incident	250,000
U.S. United Ocean Services, LLC Acquisition [Member]
Property, Plant and Equipment [Line Items]
Variance amount primarily consists of claims liabilities	2,400,000
Hull [Member]
Property, Plant and Equipment [Line Items]
Stop loss insurance policy amount	1,000,000
Machinery [Member]
Property, Plant and Equipment [Line Items]
Stop loss insurance policy amount	$ 500,000