Quarterly report pursuant to Section 13 or 15(d)

Note 4 - Long-term Debt (Details Textual)

v3.10.0.1
Note 4 - Long-term Debt (Details Textual)
$ / shares in Units, € in Millions
1 Months Ended 3 Months Ended 9 Months Ended
Sep. 26, 2018
USD ($)
May 02, 2018
USD ($)
$ / shares
shares
Feb. 08, 2018
USD ($)
Nov. 08, 2018
USD ($)
Sep. 30, 2018
USD ($)
$ / shares
Sep. 30, 2017
USD ($)
Sep. 30, 2018
USD ($)
$ / shares
Sep. 30, 2018
EUR (€)
Sep. 30, 2017
USD ($)
Oct. 31, 2018
USD ($)
Sep. 25, 2018
USD ($)
Jul. 05, 2018
USD ($)
Jun. 30, 2018
May 31, 2018
$ / shares
May 24, 2018
$ / shares
Dec. 31, 2017
$ / shares
Dec. 01, 2015
USD ($)
Debt Instrument, Interest Rate, Stated Percentage                         2.00%        
Class of Warrant or Right, Exercise Price of Warrants or Rights | $ / shares         $ 0.01   $ 0.01                  
Repayments of Long-term Debt, Total             $ 38,053,000   $ 8,572,000                
Debt Instrument, Increase (Decrease), Net, Total $ 30,100,000           1,000,000                    
Gain (Loss) on Extinguishment of Debt, Total         $ (638,000) (638,000)                  
Other Labor and Performance Guarantee         2,500,000   2,500,000                    
Long-term Debt Obligation [Member]                                  
Letters of Credit Outstanding, Amount         5,800,000   5,800,000                    
Lease Obligation [Member]                                  
Letters of Credit Outstanding, Amount         $ 300,000   $ 300,000                    
Subsequent Event [Member]                                  
Repayments of Long-term Debt, Total       $ 7,000,000                          
Falcon Global Holdings [Member]                                  
Noncontrolling Interest, Ownership Percentage by Parent         72.00%   72.00%                    
Falcon Global USA LLC [Member]                                  
Payments for Debtor-in-possession Obligations     $ 15,000,000                            
Convertible Senior Notes Converted to Warrants [Member] | Carlyle Group [Member]                                  
Debt Instrument, Convertible, Conversion Ratio   37.73                              
Class of Warrant or Right, Exercise Price of Warrants or Rights | $ / shares   $ 0.01                              
Debt Conversion, Original Debt, Amount   $ 50,000,000                              
Debt Conversion, Converted Instrument, Shares Issued | shares   1,886,792                              
Debt Instrument, Convertible, Conversion Price | $ / shares   $ 26.50                              
Conversion Revolving Credit Facility from Windcat Workboats [Member]                                  
Debt Conversion, Original Debt, Amount | €               € 6                  
Carlyle Warrants [Member]                                  
Class of Warrant or Right, Exercise Price of Warrants or Rights | $ / shares         $ 0.01   $ 0.01             $ 0.01 $ 0.01    
Warrants and Rights Outstanding, Term   25 years                              
Convertible Senior Notes 3.75% [Member]                                  
Convertible Debt, Total   $ 125,000,000                             $ 175,000,000
Debt Instrument, Interest Rate, Stated Percentage   4.25%                             3.75%
Debt Instrument, Convertible, Conversion Ratio             23.26 23.26                  
FGUSA Credit Facility [Member]                                  
Debt Agreement, Maximum Borrowing Capacity     131,100,000                            
Debt Instrument, Unamortized Discount, Total     10,000,000                            
FGUSA Credit Facility [Member] | Revolving Credit Facility [Member]                                  
Line of Credit Facility, Maximum Borrowing Capacity     15,000,000                            
Debt Instrument, Interest Rate, Effective Percentage         6.63%   6.63%                    
Proceeds from Lines of Credit, Total             $ 15                    
FGUSA Credit Facility [Member] | Term Loan [Member]                                  
Long-term Debt, Total     $ 116,100,000                            
Euro Debt [Member]                                  
Repayments of Long-term Debt, Total             7,500,000                    
Pound Sterling Debt [Member]                                  
Proceeds from Issuance of Long-term Debt, Total             $ 8,500,000                    
Term Loan to Acquire Two Vessels [Member]                                  
Debt Instrument, Interest Rate, Effective Percentage                       5.90%          
Debt Instrument, Face Amount                       $ 11,000,000          
Term Loan to Acquire Two Vessels [Member] | Interest Rate Swap [Member] | Subsequent Event [Member]                                  
Derivative, Notional Amount                   $ 5,500,000              
Loan Facility With DNB Bank ASA [Member]                                  
Line of Credit Facility, Maximum Borrowing Capacity $ 130,000,000                                
Debt Instrument, Interest Rate, Effective Percentage 6.1875%                                
Debt Instrument, Face Amount $ 130,000,000                                
Debt Instrument, Periodic Payment, Principal 3,300,000                                
Loan Facility With DNB Bank ASA [Member] | Interest Rate Swap [Member] | Subsequent Event [Member]                                  
Derivative, Notional Amount                   $ 65,500,000              
Other DNB Credit Facilities [Member]                                  
Long-term Debt, Total                     $ 99,900,000            
Repayments of Lines of Credit 101,300,000                                
Interest Payable                     $ 1,400,000            
Gain (Loss) on Extinguishment of Debt, Total $ (600,000)