v3.25.4
Note 7 - Borrowings (Details Textual)
$ / shares in Units, $ in Thousands
 12 Months Ended
Sep. 04, 2025
USD ($)
May 23, 2025
USD ($)
Apr. 25, 2025
Apr. 17, 2025
Oct. 17, 2024
USD ($)
Jun. 21, 2024
USD ($)
Jun. 20, 2024
Jun. 19, 2024
May 24, 2023
USD ($)
Dec. 31, 2025
USD ($)
$ / shares
shares
Dec. 31, 2024
USD ($)
$ / shares
Dec. 31, 2023
USD ($)
$ / shares
Dec. 15, 2025
USD ($)
Jun. 29, 2023
USD ($)
Dec. 31, 2022
USD ($)
$ / shares
Nov. 09, 2022
USD ($)
Jun. 15, 2022
USD ($)
$ / shares
Dec. 31, 2021
USD ($)
$ / shares
Mar. 30, 2021
USD ($)
$ / shares
Dec. 31, 2020
USD ($)
$ / shares
Apr. 21, 2020
USD ($)
Dec. 31, 2019
USD ($)
$ / shares
Dec. 31, 2018
USD ($)
$ / shares
Dec. 31, 2017
USD ($)
$ / shares
Dec. 31, 2016
USD ($)
$ / shares
Dec. 31, 2015
$ / shares
Restricted Investments                   $ 2,463 $ 3,338                              
Debt Instrument, Unamortized Discount (Premium) and Debt Issuance Costs, Net                   4,723 4,174                              
Long-Term Debt, Gross [1]                   477,750 472,078 $ 466,000     $ 439,323     $ 260,250   $ 187,625   $ 154,375 $ 127,875 $ 95,375 $ 96,000  
Debt Instrument, Face Amount                   $ 806,750 $ 716,078                              
Share Price (in dollars per share) | $ / shares                   $ 6.45 $ 8.99 $ 13.17     $ 11.6     $ 15.92   $ 13.24   $ 12.93 $ 11.25 $ 11.22 $ 10.53 $ 11.73
Debt Conversion, Original Debt, Amount                   $ 25,750 $ 0 $ 0                            
Conversion of 2030 Notes Into Common Stock [Member]                                                    
Debt Conversion, Original Debt, Amount                   $ 8,500                                
Debt Conversion, Converted Instrument, Shares Issued (in shares) | shares                   1,197,288                                
Debt Instrument, Convertible, Weighted Average Conversion Price (in dollars per share) | $ / shares                   $ 7.11                                
Debt Instrument, Convertible, Accelerated Unamortized Debt Issuance Costs                   $ 800                                
Conversion of 2031 Notes Into Common Stock [Member]                                                    
Debt Conversion, Original Debt, Amount                   $ 17,300                                
Debt Conversion, Converted Instrument, Shares Issued (in shares) | shares                   2,264,546                                
Debt Instrument, Convertible, Weighted Average Conversion Price (in dollars per share) | $ / shares                   $ 7.69                                
Debt Instrument, Convertible, Accelerated Unamortized Debt Issuance Costs                   $ 1,200                                
Key Facility [Member]                                                    
Line of Credit Facility, Maximum Borrowing Capacity, Accordian Feature                           $ 150,000                        
Line of Credit Facility, Maximum Borrowing Capacity                           $ 300,000                        
Line of Credit Facility, Advance Rate of Eligible Debt Investments                           60.00%                        
Long-Term Debt, Weighted Average Interest Rate, over Time                   7.47% 8.48%                              
Line of Credit Facility, Unused Capacity, Commitment Fee Percentage                   0.75%                                
Line of Credit Facility, Current Borrowing Capacity                   $ 150,000 $ 150,000                              
Line of Credit Facility, Remaining Borrowing Capacity                   49,600 24,800                              
Long-Term Debt, Gross                   0 0                              
Debt Instrument, Face Amount                   $ 150,000 $ 150,000                              
Key Facility [Member] | Prime Rate [Member]                                                    
Debt Instrument, Basis Spread on Variable Rate             0.10% 0.25%                                    
Debt Instrument, Variable Rate                   6.75% 7.50%                              
NYL Facility [Member]                                                    
Line of Credit Facility, Maximum Borrowing Capacity                 $ 250,000                       $ 100,000          
Line of Credit Facility, Current Borrowing Capacity                   $ 69,000 $ 69,000                              
Line of Credit Facility, Remaining Borrowing Capacity                   1,900 8,400                              
Line of Credit Facility, Maximum Borrowing Capacity, Accordion Feature                                         $ 200,000          
Line of Credit Facility, Advance Rate                                         67.00%          
Line of Credit Facility, Change in Maximum Borrowing Capacity                 $ 50,000                                  
Debt Instrument, Interest Rate, Stated Percentage                 4.60%                                  
Long-Term Line of Credit                   $ 181,000 $ 181,000                              
Line of Credit Facility, Interest Rate at Period End                   6.57% 6.47%                              
Restricted Investments                   $ 1,400 $ 1,400                              
Long-Term Debt, Gross                   181,000 181,000                              
Debt Instrument, Face Amount                   250,000 250,000                              
NYL Facility [Member] | Three Year I Curve [Member]                                                    
Debt Instrument, Basis Spread on Variable Rate     2.95%                                              
Nuveen Facility [Member]                                                    
Line of Credit Facility, Maximum Borrowing Capacity, Accordian Feature           $ 200,000                                        
Line of Credit Facility, Maximum Borrowing Capacity   $ 200,000       $ 100,000                                        
Line of Credit Facility, Current Borrowing Capacity                   110,000 25,000                              
Line of Credit Facility, Remaining Borrowing Capacity                   12,100 9,900                              
Line of Credit Facility, Advance Rate           67.50%                                        
Line of Credit Facility, Change in Maximum Borrowing Capacity   $ 100,000                                                
Long-Term Line of Credit                   $ 90,000 $ 75,000                              
Line of Credit Facility, Interest Rate at Period End                   7.21% 7.14%                              
Restricted Investments                   $ 1,100 $ 1,000                              
Long-Term Debt, Gross                   90,000 75,000                              
Debt Instrument, Face Amount                   200,000 100,000                              
Nuveen Facility [Member] | Selected Interest Rates (Daily) [Member]                                                    
Debt Instrument, Basis Spread on Variable Rate   2.95%       3.15%                                        
Asset-backed Notes 2022 [Member]                                                    
Debt Instrument, Interest Rate, Stated Percentage                               7.56%                    
Restricted Investments                     1,000                              
Debt Instrument, Unamortized Discount (Premium) and Debt Issuance Costs, Net                   900                                
Long-Term Debt, Gross                   0 81,078                              
Debt Instrument, Face Amount                   0 81,078         $ 157,800                    
The 2026 Notes [Member]                                                    
Debt Instrument, Interest Rate, Stated Percentage                                     4.875%              
Long-Term Debt, Gross [2]                   57,500 57,500 57,500     $ 57,500     $ 57,500   $ 0   $ 0 $ 0 $ 0 $ 0  
Debt Instrument, Face Amount                   57,500 57,500               $ 57,500              
The 2026 Notes Underwriter Option [Member]                                                    
Debt Instrument, Face Amount                                     $ 7,500              
Debt Instrument, Convertible, Conversion Price (in dollars per share) | $ / shares                                     $ 25              
The 2027 Notes [Member]                                                    
Debt Instrument, Interest Rate, Stated Percentage                                 6.25%                  
Long-Term Debt, Gross [2]                   57,500 57,500 57,500     57,500     0   0   0 0 0 0  
Debt Instrument, Face Amount                   57,500 57,500           $ 50,000                  
The 2027 Notes Underwriter Option [Member]                                                    
Debt Instrument, Face Amount                                 $ 7,500                  
Debt Instrument, Convertible, Conversion Price (in dollars per share) | $ / shares                                 $ 25                  
The 2028 Notes [Member]                                                    
Debt Instrument, Interest Rate, Stated Percentage                         7.00%                          
Long-Term Debt, Gross [2]                   57,500 0 0     0     0   0   0 0 0 0  
Debt Instrument, Face Amount                   $ 57,500 0   $ 57,500                          
Debt Instrument, Redemption Price, Percentage                   100.00%                                
The 2028 Notes [Member] | Treasury Rate [Member]                                                    
Debt Instrument, Basis Spread on Variable Rate                   0.50%                                
The 2030 Convertible Notes [Member]                                                    
Debt Instrument, Interest Rate, Stated Percentage 5.50%                 5.50%                                
Long-Term Debt, Gross [2]                   $ 31,500 0 0     0     0   0   0 0 0 0  
Debt Instrument, Face Amount $ 40,000                 $ 31,500 0                              
Debt Instrument, Convertible, Conversion Price (in dollars per share) | $ / shares                   $ 7.12                                
Debt Instrument, Redemption Price, Percentage                   100.00%                                
Proceeds from Convertible Debt $ 36,600                 $ 40,000 0 0                            
Debt Instrument, Convertible, Threshold Consecutive Trading Days                   5                                
Debt Instrument, Convertible, Number of Equity Instruments                   4,424,157                                
Share Price (in dollars per share) | $ / shares                   $ 6.45                                
Debt Instrument, Convertible, Maximum Beneficial Ownership Percentage                   4.99%                                
Convertible Debt                   $ 31,500 0 0                            
Debt Instrument, Maturity Date Sep. 04, 2030                                                  
The 2031 Convertible Notes [Member]                                                    
Debt Instrument, Interest Rate, Stated Percentage         7.125%                                          
Long-Term Debt, Gross [2]                   2,750 20,000 0     $ 0     $ 0   $ 0   $ 0 $ 0 $ 0 $ 0  
Debt Instrument, Face Amount         $ 20,000         $ 2,750 20,000                              
Debt Instrument, Convertible, Conversion Price (in dollars per share) | $ / shares                   $ 7.12                                
Debt Instrument, Redemption Price, Percentage       100.00% 100.00%                                          
Proceeds from Convertible Debt         $ 18,600         $ 0 $ 20,000 0                            
Debt Instrument, Convertible, Threshold Consecutive Trading Days                   5 5                              
Debt Instrument, Convertible, Number of Equity Instruments                   386,236                                
Debt Instrument, Convertible, Maximum Beneficial Ownership Percentage         4.99%                                          
Convertible Debt                   $ 2,800 $ 20,000 $ 0                            
Debt Instrument, Interest Rate, Increase From Failure to Maintain Investment Rating         1.00%                                          
Debt Instrument, Interest Rate, Increase From Default         2.00%                                          
Debt Instrument, Maturity Date         Oct. 17, 2031                                          
Minimum [Member]                                                    
Asset Coverage to Borrowings, Ratio, Percent                   150.00%                                
Minimum [Member] | Key Facility [Member] | Prime Rate [Member]                                                    
Debt Instrument, Basis Spread on Variable Rate             4.10% 4.25%                                    
Minimum [Member] | Nuveen Facility [Member]                                                    
Debt Instrument, Interest Rate, Stated Percentage   5.00%       5.00%                                        
Minimum [Member] | Nuveen Facility [Member] | Selected Interest Rates (Daily) [Member]                                                    
Debt Instrument, Basis Spread on Variable Rate, Treasury Yield Maturity (Year)           3 years                                        
Maximum [Member]                                                    
Asset Coverage to Borrowings, Ratio, Percent                   167.00%                                
Maximum [Member] | Nuveen Facility [Member] | Selected Interest Rates (Daily) [Member]                                                    
Debt Instrument, Basis Spread on Variable Rate, Treasury Yield Maturity (Year)           5 years                                        
Weighted Average [Member] | Nuveen Facility [Member] | Selected Interest Rates (Daily) [Member]                                                    
Debt Instrument, Basis Spread on Variable Rate, Treasury Yield Maturity (Year)           4 years 10 months 17 days                                        
[1] Total amount of senior securities outstanding at the end of the period presented.
[2] Total amount of senior securities outstanding at the end of the period presented.