Quarterly report pursuant to Section 13 or 15(d)

Note 6 - Derivative Instruments and Hedging Strategies (Details Textual)

v3.10.0.1
Note 6 - Derivative Instruments and Hedging Strategies (Details Textual) - Interest Rate Swap [Member]
€ in Millions, $ in Millions
Jun. 30, 2018
USD ($)
Jun. 30, 2018
EUR (€)
Falcon Global [Member]    
Derivative, Fixed Interest Rate 2.06% 2.06%
Derivative, Notional Amount $ 53.1  
OSV Partners [Member]    
Derivative, Number of Instruments Held, Total 2 2
OSV Partners [Member] | Minimum [Member]    
Derivative, Fixed Interest Rate 1.89% 1.89%
OSV Partners [Member] | Maximum [Member]    
Derivative, Fixed Interest Rate 2.27% 2.27%
Derivative, Notional Amount $ 30.4  
Designated as Hedging Instrument [Member] | Cash Flow Hedging [Member]    
Derivative, Number of Instruments Held, Total 2 2
Derivative, Fixed Interest Rate 0.03% 0.03%
Derivative, Notional Amount $ 17.5 € 15
Designated as Hedging Instrument [Member] | Cash Flow Hedging [Member] | MexMar [Member]    
Derivative, Number of Instruments Held, Total 5 5
Derivative, Notional Amount $ 104.0  
Designated as Hedging Instrument [Member] | Cash Flow Hedging [Member] | MexMar [Member] | Minimum [Member]    
Derivative, Fixed Interest Rate 1.71% 1.71%
Designated as Hedging Instrument [Member] | Cash Flow Hedging [Member] | MexMar [Member] | Maximum [Member]    
Derivative, Fixed Interest Rate 2.10% 2.10%
Designated as Hedging Instrument [Member] | Cash Flow Hedging [Member] | Sea-Cat Crewzer II [Member]    
Derivative, Fixed Interest Rate 1.52% 1.52%
Derivative, Notional Amount $ 19.7  
Designated as Hedging Instrument [Member] | Cash Flow Hedging [Member] | Sea-Cat Crewzer [Member]    
Derivative, Fixed Interest Rate 1.52% 1.52%
Derivative, Notional Amount $ 17.4