BUSINESS AND SEGMENT REPORTING (Details) (USD $) In Thousands, unless otherwise specified	1 Months Ended			2 Months Ended	3 Months Ended	12 Months Ended			3 Months Ended	12 Months Ended
	Oct. 31, 2011	Jun. 30, 2010	Mar. 31, 2010	Dec. 31, 2012	Dec. 31, 2012	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Sep. 30, 2010 Us Flag [Member]	Dec. 31, 2012 Us Flag [Member]	Dec. 31, 2011 Us Flag [Member]	Dec. 31, 2010 Us Flag [Member]	Dec. 31, 2012 Reportable Segment [Member] International Crude Tankers Segment [Member]	Dec. 31, 2011 Reportable Segment [Member] International Crude Tankers Segment [Member]	Dec. 31, 2010 Reportable Segment [Member] International Crude Tankers Segment [Member]	Dec. 31, 2012 Reportable Segment [Member] International Product Carriers Segment [Member]	Dec. 31, 2011 Reportable Segment [Member] International Product Carriers Segment [Member]	Dec. 31, 2010 Reportable Segment [Member] International Product Carriers Segment [Member]	Dec. 31, 2012 Reportable Segment [Member] International Other Segment [Member]	Dec. 31, 2011 Reportable Segment [Member] International Other Segment [Member]	Dec. 31, 2010 Reportable Segment [Member] International Other Segment [Member]	Dec. 31, 2012 Reportable Segment [Member] Us Flag [Member]	Dec. 31, 2011 Reportable Segment [Member] Us Flag [Member]	Dec. 31, 2010 Reportable Segment [Member] Us Flag [Member]
Shipping revenues						$ 1,137,134	$ 1,049,531	$ 1,045,610		$ 451,803	$ 377,787	$ 288,249	$ 343,541	$ 337,137	$ 497,367	$ 331,634	$ 321,322	$ 247,779	$ 10,156	$ 13,285	$ 12,215	$ 451,803	$ 377,787	$ 288,249
Time charter equivalent revenues						840,846	790,201	853,278					256,843	266,429	422,970	171,881	178,823	167,543	10,071	13,228	12,215	402,051	331,721	250,550
Depreciation and amortization						201,284	179,721	170,670					83,558	74,392	73,399	43,239	35,385	30,386	5,392	5,809	6,152	69,095	64,135	60,733
Shipyard contract termination recoveries						0	0	(2,061)							0			0			0			2,061
Gain/(loss) on disposal of vessels	1,464			(98)	8,078	(271,359)	2,060	161	679				(102,242)	673	1,351	(160,706)	(71)	21	8,085	(29)	(2,287)	(16,496)	1,487	1,076
Loss on write-down of vessels		25,176	3,607			279,382	0	28,783							12,730			0			0			16,053
Income/(loss) from vessel operations						(15,866)	(61,070)	47,690					(70,909)	(71,033)	62,283	(59,111)	(42,021)	(24,698)	(4,243)	(828)	(562)	118,397	52,812	10,667
Equity in income of affiliated companies						33,486	20,555	3,593					18,658	8,985	(7,881)	0	0	0	11,378	7,157	7,091	3,450	4,413	4,383
Investments in affiliated companies at December 31				252,398	252,398	252,398	232,370	265,096					241,198	211,406	214,099	6,000	3,855	1,800	1,700	12,669	44,771	3,500	4,440	4,426
Total assets at December 31				4,043,535	4,043,535	4,043,535	3,993,545	3,854,237					1,739,740	1,848,531	1,876,643	620,731	878,885	790,962	2,333	22,395	53,727	1,123,368	1,125,634	1,132,905
Expenditures for vessels						52,604	187,510	421,363					33,488	45,654	55,810	18,563	79,492	151,110	6	0	0	547	62,364	214,443
Payments for drydocking						$ 45,990	$ 47,360	$ 20,015					$ 20,063	$ 16,600	$ 9,203	$ 7,166	$ 14,166	$ 1,079	$ 0	$ 0	$ 1,000	$ 18,761	$ 16,594	$ 8,733