Quarterly report pursuant to Section 13 or 15(d)

Note 7 - Fair Value Measurements (Details Textual)

v3.10.0.1
Note 7 - Fair Value Measurements (Details Textual)
$ in Millions
6 Months Ended
Jun. 30, 2018
USD ($)
Impairment of Long-Lived Assets Held-for-use $ 3.0
Minimum [Member] | Economic Obsolesence Factor [Member]  
Property and Equipment, Measurement Input 0.45
Maximum [Member] | Economic Obsolesence Factor [Member]  
Property and Equipment, Measurement Input 0.5
Liftboats [Member] | Minimum [Member]  
Property, Plant and Equipment, Useful Life 25 years
Liftboats [Member] | Maximum [Member]  
Property, Plant and Equipment, Useful Life 40 years
Debt Assumed from FGUSA [Member]  
Long-term Debt, Total $ 121.6