Note 3 - Vessel Acquisitions and Dispositions (Details) - Vessels Acquired (Highland Duke [Member], Large Platform Supply Vessel [Member], North Sea [Member])	9 Months Ended
	Sep. 30, 2014 hp T ft
Highland Duke [Member] | Large Platform Supply Vessel [Member] | North Sea [Member]
Significant Acquisitions and Disposals [Line Items]
Highland Duke	2012
Highland Duke	246
Highland Duke	7,483	[1]
Highland Duke	3,133	[2]
Highland Duke	Feb-14

[1] BHP - Brake Horsepower

[2] DWT - Deadweight Tons