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REVENUE (Details) (USD $)	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
REVENUE [Abstract]
Total number of vessels	20	17	15
Number of vessels temporarily operated directly in the spot market	6	0	4
Number of vessels were employed on bareboat charters		2	2
Voyage revenues, net pool earnings	$ 76,618,000	$ 119,598,000	$ 102,229,000
Voyage revenues, gross freight through spot charters	18,169,000	0	15,817,000
Bareboat revenues	0	6,818,000	6,324,000
Total Voyage Revenues	94,787,000	126,416,000	124,370,000
Concentration Risk [Line Items]
Accounts receivable	17,586,000	11,046,000
Accounts receivable, net related party	$ 1,600,000
Voyage Revenues [Member] | Gemini Tankers LLC [Member]
Concentration Risk [Line Items]
Concentration risk, percentage (in hundredths)	97.00%	78.00%
Voyage Revenues [Member] | Orion Pool [Member]
Concentration Risk [Line Items]
Concentration risk, percentage (in hundredths)	3.00%
Voyage Revenues [Member] | Stena Pool [Member]
Concentration Risk [Line Items]
Concentration risk, percentage (in hundredths)		17.00%	41.00%
Voyage Revenues [Member] | Gemini Pool [Member]
Concentration Risk [Line Items]
Concentration risk, percentage (in hundredths)			40.00%
Accounts Receivable [Member] | Gemini Tankers LLC [Member]
Concentration Risk [Line Items]
Concentration risk, percentage (in hundredths)	99.00%	100.00%
Accounts Receivable [Member] | Stena Pool [Member]
Concentration Risk [Line Items]
Concentration risk, percentage (in hundredths)			61.00%
Accounts Receivable [Member] | Gemini Pool [Member]
Concentration Risk [Line Items]
Concentration risk, percentage (in hundredths)			33.00%
Accounts Receivable, Net Related Party [Member] | Orion Pool [Member]
Concentration Risk [Line Items]
Concentration risk, percentage (in hundredths)	100.00%

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The total number of vessels during the period, which may include crude oil tankers and new vessels under construction to be used in the normal conduct of business and not intended for resale.

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Amount of receivables arising from transactions with related parties due within one year or the normal operating cycle, if longer.

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