SEGMENT DATA (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2015 USD ($)	Sep. 30, 2014 USD ($)	Sep. 30, 2015 USD ($) Segment	Sep. 30, 2014 USD ($)	Dec. 31, 2014 USD ($)
SEGMENT DATA [Abstract]
Number of reportable segments | Segment			2
Revenues [Abstract]
Marine transportation	$ 418,343,000	$ 448,744,000	$ 1,263,301,000	$ 1,341,260,000
Diesel engine services	114,222,000	231,977,000	400,093,000	556,761,000
Total revenues	532,565,000	680,721,000	1,663,394,000	1,898,021,000
Segment profit (loss)	90,623,000	122,928,000	281,597,000	345,607,000
Total assets	4,165,939,000		4,165,939,000		$ 4,141,909,000
Other segment disclosures [Abstract]
Gain (loss) on disposition of assets	(400,000)	47,000	1,246,000	625,000
Interest expense	(4,449,000)	(5,225,000)	(14,458,000)	(16,312,000)
Other income (expense)	22,000	27,000	(221,000)	(86,000)
Prepaid Expenses and Other Current Assets [Member]
Asset Purchase Agreement [Abstract]
Assets held for sale, current	18,415,000		18,415,000
Accrued Liabilities [Member]
Asset Purchase Agreement [Abstract]
Liabilities held for sale, current	6,158,000		6,158,000
Other [Member]
Revenues [Abstract]
Segment profit (loss)	(8,638,000)	(9,240,000)	(24,718,000)	(27,189,000)
Total assets	47,781,000		47,781,000		88,084,000
Other segment disclosures [Abstract]
General corporate expenses	(3,811,000)	(4,089,000)	(11,285,000)	(11,416,000)
Gain (loss) on disposition of assets	(400,000)	47,000	1,246,000	625,000
Interest expense	(4,449,000)	(5,225,000)	(14,458,000)	(16,312,000)
Other income (expense)	22,000	27,000	(221,000)	(86,000)
Profit (loss) from other segment	(8,638,000)	(9,240,000)	(24,718,000)	(27,189,000)
Details of "Other" total assets [Abstract]
General corporate assets	45,812,000		45,812,000		85,545,000
Investment in affiliates	1,969,000		1,969,000		2,539,000
Total other assets	47,781,000		47,781,000		88,084,000
Reporting Segments [Member] | Marine transportation [Member]
Revenues [Abstract]
Marine transportation	418,343,000	448,744,000	1,263,301,000	1,341,260,000
Segment profit (loss)	93,650,000	112,141,000	286,930,000	325,660,000
Total assets	3,443,971,000		3,443,971,000		3,317,696,000
Reporting Segments [Member] | Diesel engine services [Member]
Revenues [Abstract]
Diesel engine services	114,222,000	231,977,000	400,093,000	556,761,000
Segment profit (loss)	5,611,000	$ 20,027,000	19,385,000	$ 47,136,000
Total assets	$ 674,187,000		$ 674,187,000		$ 736,129,000