Note 3 - Vessel Acquisitions and Dispositions (Details) - Vessels Disposed (Southeast Asia [Member])	9 Months Ended
	Sep. 30, 2014 T hp ft
Highland Piper [Member] | Large Platform Supply Vessel [Member]
Significant Acquisitions and Disposals [Line Items]
Year Built	1996
Length (feet) (in Feet)	221
BHP (in Horsepower)	5,450	[1]
DWT (in US tons)	3,115	[2]
Month Disposed	Jul-14
Highland Legend [Member] | Platform Supply Vessel [Member]
Significant Acquisitions and Disposals [Line Items]
Year Built	1986
Length (feet) (in Feet)	194
BHP (in Horsepower)	3,600
DWT (in US tons)	1,442
Month Disposed	Sep-14

[1] BHP - Brake Horsepower

[2] DWT - Deadweight Tons