EQUITY METHOD INVESTMENTS (Details Textual) (USD $) In Thousands, unless otherwise specified	12 Months Ended								1 Months Ended	12 Months Ended			12 Months Ended				12 Months Ended		12 Months Ended
	Dec. 31, 2012 Numbers	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2012 Ti Africa Vessel [Member]	Dec. 31, 2011 Ti Africa Vessel [Member]	Dec. 31, 2010 Ti Africa Vessel [Member]	Dec. 31, 2012 Qatar Gas Transport Company Limited Nakilat Joint Venture [Member] Liquid Natural Gas Carrier Vessel [Member] Minimum [Member]	Dec. 31, 2012 Qatar Gas Transport Company Limited Nakilat Joint Venture [Member] Liquid Natural Gas Carrier Vessel [Member] Maximum [Member]	Nov. 30, 2004 Qatar Gas Transport Company Limited Nakilat Joint Venture and Euronav Nv Joint Venture [Member]	Dec. 31, 2012 Qatar Gas Transport Company Limited Nakilat Joint Venture and Euronav Nv Joint Venture [Member]	Dec. 31, 2012 Euronav Nv Joint Venture [Member]	Dec. 31, 2011 Euronav Nv Joint Venture [Member]	Dec. 31, 2012 Euronav Nv Joint Venture [Member] Minimum [Member]	Dec. 31, 2012 Euronav Nv Joint Venture [Member] Maximum [Member]	Dec. 31, 2012 Euronav Nv Joint Venture [Member] Ti Africa Vessel [Member]	Dec. 31, 2010 Euronav Nv Joint Venture [Member] Ti Africa Vessel [Member]	Dec. 31, 2012 Euronav Nv Joint Venture [Member] Ti Asia Vessel [Member]	Dec. 31, 2012 Alaska Tanker Company LLC [Member]	Dec. 31, 2012 Qatar Liquefied Gas Company Limited [Member] Liquid Natural Gas Carrier Vessel [Member]	Dec. 31, 2011 Qatar Liquefied Gas Company Limited [Member] Liquid Natural Gas Carrier Vessel [Member]
Storage Volume									216,200 cbm
Equity Method Investment, Ownership Percentage	50.00%								49.90%	50.00%	50.00%							37.50%
Equity Method Investment, Description of Principal Activities									Ordered four 216,200 cbm LNG Carriers	Operates four LNG Carriers	Maersk Oil Qatar AS (“MOQ”) awarded two service contracts to a joint venture between OSG and Euronav NV
Non-Recourse Debt	$ 783,839	$ 815,151
Line of Credit Facility, Amount Outstanding											246,326	294,937
Guarantee Obligations Noncurrent Carrying Value											29	122
Notional Amount of Interest Rate Cash Flow Hedge Derivatives											351,987	396,993
Derivative, Fixed Interest Rate	3.90%									4.90%	3.90%
Gain (Loss) on Discontinuation of Interest Rate Cash Flow Hedge Due to Forecasted Transaction Probable of Not Occurring, Net				2,216	6,574	9,885													181,959	180,696
Interest Rate Cash Flow Hedge Liability at Fair Value				10,053	9,339						34,872	39,136
Derivative, Maturity Date							Jul. 01, 2022	Nov. 30, 2022					Jul. 01, 2017	Sep. 30, 2017
Number Of Joint Ventures	3
Converted vessels put in service															Aug. 30, 2010		Jan. 05, 2010
Contract Expected Delivery Date															Jan. 19, 2010
Contract Cancellation Date															Jan. 21, 2010
Line of Credit Facility, Current Borrowing Capacity																120,000
Guarantor Obligations, Liquidation Proceeds, Percentage											50.00%
Reconditioned Asset Date Completed															Mar. 14, 2010
Due from Joint Ventures			1,332
Amount Eliminated From Income Loss From Equity Method Investments and Revenues			666
Ineffective Portion	0	0	6																760,293	790,946
Effective Portion of Gain/(Loss) Reclassified from Accumulated Other Comprehensive Loss	(6,096)	(8,194)	(12,014)																90,731	90,100
Increase (Decrease) Due from Affiliates	4,103
Debt Instrument Amount Outstanding	1,030,165	1,110,088
Allowance for Funds Used During Construction, Capitalized Interest			$ 509