Note 3 - Vessel Acquisitions and Dispositions (Details) - Vessel Additions (Large Platform Supply Vessel [Member])	9 Months Ended
	Sep. 30, 2014 T hp ft
North Cruys [Member] | North Sea [Member]
Significant Acquisitions and Disposals [Line Items]
Year Built	2014
Length (feet)	304
BHP	11,935	[1]
DWT	4,700	[2]
Month Delivered	Feb-14
Highland Princess [Member] | North Sea [Member]
Significant Acquisitions and Disposals [Line Items]
Year Built	2014
Length (feet)	246
BHP	8,487	[1]
DWT	3,900	[2]
Month Delivered	Mar-14
Polaris [Member] | Americas [Member]
Significant Acquisitions and Disposals [Line Items]
Year Built	2014
Length (feet)	271
BHP	9,990	[1]
DWT	3,600	[2]
Month Delivered	Apr-14

[1] BHP - Brake Horsepower

[2] DWT - Deadweight Tons