Note 2 - Vessel Acquisitions and Dispositions (Details) - Vessels Additions Since December 31, 2012	9 Months Ended
	Sep. 30, 2013 ft T hp
Significant Acquisitions and Disposals [Line Items]
Length (feet) (in Feet)	271
BHP (in Horsepower)	9,990
DWT (in US Ton)	3,600
LgSPV [Member] | Highland Defender [Member] | North Sea [Member]
Significant Acquisitions and Disposals [Line Items]
Year Built	2013
Length (feet) (in Feet)	291
BHP (in Horsepower)	9,574	[1]
DWT (in US Ton)	5,100	[2]
Month Delivered	Jul-13
LgSPV [Member] | North Pomor [Member] | North Sea [Member]
Significant Acquisitions and Disposals [Line Items]
Year Built	2013
Length (feet) (in Feet)	304
BHP (in Horsepower)	11,935	[1]
DWT (in US Ton)	4,700	[2]
Month Delivered	Jul-13
LgSPV [Member] | Highland Chieftain [Member] | North Sea [Member]
Significant Acquisitions and Disposals [Line Items]
Year Built	2013
Length (feet) (in Feet)	260
BHP (in Horsepower)	9,574	[1]
DWT (in US Ton)	4,000	[2]
Month Delivered	Sep-13
LgSPV [Member] | Highland Guardian [Member] | North Sea [Member]
Significant Acquisitions and Disposals [Line Items]
Year Built	2013
Length (feet) (in Feet)	291
BHP (in Horsepower)	9,574	[1]
DWT (in US Ton)	5,100	[2]
Month Delivered	Sep-13
LgSPV [Member] | Polaris [Member] | Americas [Member]
Significant Acquisitions and Disposals [Line Items]
Year Built	2013
Length (feet) (in Feet)	246
BHP (in Horsepower)	8,457	[1]
DWT (in US Ton)	3,000	[2]
Month Delivered	Oct-13

[1] BHP - Brake Horsepower

[2] DWT - Deadweight Tons