Quarterly report [Sections 13 or 15(d)]

Fair Value of Financial Instruments - Schedule of Fair Value Hierarchy of Outstanding Borrowings (Details)

v3.26.1
Fair Value of Financial Instruments - Schedule of Fair Value Hierarchy of Outstanding Borrowings (Details) - USD ($)
$ / shares in Units, $ in Thousands
Mar. 31, 2026
Dec. 31, 2025
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Carrying Value $ 2,539,032 $ 2,286,444
Carrying Value    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Carrying Value 2,539,032 2,286,444
Fair Value    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Approximate Fair Value 2,523,467 2,293,046
SBA Debentures | Carrying Value    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Carrying Value 341,301 341,012
SBA Debentures | Fair Value    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Approximate Fair Value 333,445 335,905
September 2026 Notes | Carrying Value    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Carrying Value 324,548 324,302
September 2026 Notes | Fair Value    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Approximate Fair Value 321,090 320,186
January 2027 Notes | Carrying Value    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Carrying Value 348,928 348,596
January 2027 Notes | Fair Value    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Approximate Fair Value 344,127 $ 346,365
2028 Convertible Notes    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Current price per par value (in dollars per share)   $ 0.998
2028 Convertible Notes | Carrying Value    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Carrying Value 281,076 $ 280,412
2028 Convertible Notes | Fair Value    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Approximate Fair Value 280,152 286,870
February 2029 Notes | Carrying Value    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Carrying Value 294,267  
February 2029 Notes | Fair Value    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Approximate Fair Value 294,756  
June 2030 Notes | Carrying Value    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Carrying Value 343,104 342,694
June 2030 Notes | Fair Value    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Approximate Fair Value 344,617 352,274
March 2026 A Notes | Carrying Value    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Carrying Value   49,984
March 2026 A Notes | Fair Value    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Approximate Fair Value   50,615
March 2026 B Notes | Carrying Value    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Carrying Value   49,983
March 2026 B Notes | Fair Value    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Approximate Fair Value   $ 50,627
2031 Asset-Backed Notes    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Current price per par value (in dollars per share)   $ 0.982
2031 Asset-Backed Notes | Carrying Value    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Carrying Value 64,466 $ 64,530
2031 Asset-Backed Notes | Fair Value    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Approximate Fair Value $ 63,325 $ 63,486
2033 Notes    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Current price per par value (in dollars per share) $ 24.78 $ 25.49
2033 Notes | Underwriting    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Current price per par value (in dollars per share) $ 25.00 $ 25.00
2033 Notes | Carrying Value    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Carrying Value $ 39,178 $ 39,151
2033 Notes | Fair Value    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Approximate Fair Value 39,648 40,784
MUFG Bank Facility | Carrying Value    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Carrying Value 220,000 168,000
MUFG Bank Facility | Fair Value    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Approximate Fair Value 220,000 168,000
SMBC Facility | Carrying Value    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Carrying Value 282,164 277,780
SMBC Facility | Fair Value    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Approximate Fair Value 282,307 277,934
Identical Assets (Level 1) | Fair Value    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Approximate Fair Value 0 0
Identical Assets (Level 1) | SBA Debentures | Fair Value    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Approximate Fair Value 0 0
Identical Assets (Level 1) | September 2026 Notes | Fair Value    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Approximate Fair Value 0 0
Identical Assets (Level 1) | January 2027 Notes | Fair Value    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Approximate Fair Value 0 0
Identical Assets (Level 1) | 2028 Convertible Notes | Fair Value    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Approximate Fair Value 0 0
Identical Assets (Level 1) | February 2029 Notes | Fair Value    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Approximate Fair Value 0  
Identical Assets (Level 1) | June 2030 Notes | Fair Value    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Approximate Fair Value 0 0
Identical Assets (Level 1) | March 2026 A Notes | Fair Value    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Approximate Fair Value   0
Identical Assets (Level 1) | March 2026 B Notes | Fair Value    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Approximate Fair Value   0
Identical Assets (Level 1) | 2031 Asset-Backed Notes | Fair Value    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Approximate Fair Value 0 0
Identical Assets (Level 1) | 2033 Notes | Fair Value    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Approximate Fair Value 0 0
Identical Assets (Level 1) | MUFG Bank Facility | Fair Value    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Approximate Fair Value 0 0
Identical Assets (Level 1) | SMBC Facility | Fair Value    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Approximate Fair Value 0 0
Observable Inputs (Level 2) | Fair Value    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Approximate Fair Value 1,687,715 391,140
Observable Inputs (Level 2) | SBA Debentures | Fair Value    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Approximate Fair Value $ 0 0
Observable Inputs (Level 2) | SBA Debentures | Fair Value | Market Comparable Companies    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Current price per par value (in dollars per share) $ 0  
Observable Inputs (Level 2) | September 2026 Notes | Fair Value    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Approximate Fair Value $ 321,090 0
Observable Inputs (Level 2) | September 2026 Notes | Fair Value | Market Comparable Companies    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Current price per par value (in dollars per share) $ 0.988  
Observable Inputs (Level 2) | January 2027 Notes | Fair Value    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Approximate Fair Value $ 344,127 0
Observable Inputs (Level 2) | January 2027 Notes | Fair Value | Market Comparable Companies    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Current price per par value (in dollars per share) $ 0.983  
Observable Inputs (Level 2) | 2028 Convertible Notes | Fair Value    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Approximate Fair Value $ 280,152 286,870
Observable Inputs (Level 2) | 2028 Convertible Notes | Fair Value | Market Comparable Companies    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Current price per par value (in dollars per share) $ 0.974  
Observable Inputs (Level 2) | February 2029 Notes | Fair Value    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Approximate Fair Value $ 294,756  
Observable Inputs (Level 2) | February 2029 Notes | Fair Value | Market Comparable Companies    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Current price per par value (in dollars per share) $ 0.983  
Observable Inputs (Level 2) | June 2030 Notes | Fair Value    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Approximate Fair Value $ 344,617 0
Observable Inputs (Level 2) | June 2030 Notes | Fair Value | Market Comparable Companies    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Current price per par value (in dollars per share) $ 0.985  
Observable Inputs (Level 2) | March 2026 A Notes | Fair Value    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Approximate Fair Value   0
Observable Inputs (Level 2) | March 2026 B Notes | Fair Value    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Approximate Fair Value   0
Observable Inputs (Level 2) | 2031 Asset-Backed Notes | Fair Value    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Approximate Fair Value $ 63,325 63,486
Observable Inputs (Level 2) | 2031 Asset-Backed Notes | Fair Value | Market Comparable Companies    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Current price per par value (in dollars per share) $ 0.982  
Observable Inputs (Level 2) | 2033 Notes | Fair Value    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Approximate Fair Value $ 39,648 40,784
Observable Inputs (Level 2) | 2033 Notes | Fair Value | Market Comparable Companies    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Current price per par value (in dollars per share) $ 0.991  
Observable Inputs (Level 2) | MUFG Bank Facility | Fair Value    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Approximate Fair Value $ 0 0
Observable Inputs (Level 2) | MUFG Bank Facility | Fair Value | Market Comparable Companies    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Current price per par value (in dollars per share) $ 0  
Observable Inputs (Level 2) | SMBC Facility | Fair Value    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Approximate Fair Value $ 0 0
Observable Inputs (Level 2) | SMBC Facility | Fair Value | Market Comparable Companies    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Current price per par value (in dollars per share) $ 0  
Unobservable Inputs (Level 3) | Fair Value    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Approximate Fair Value $ 835,752 1,901,906
Unobservable Inputs (Level 3) | SBA Debentures | Fair Value    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Approximate Fair Value 333,445 335,905
Unobservable Inputs (Level 3) | September 2026 Notes | Fair Value    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Approximate Fair Value 0 320,186
Unobservable Inputs (Level 3) | January 2027 Notes | Fair Value    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Approximate Fair Value 0 346,365
Unobservable Inputs (Level 3) | 2028 Convertible Notes | Fair Value    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Approximate Fair Value 0 0
Unobservable Inputs (Level 3) | February 2029 Notes | Fair Value    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Approximate Fair Value 0  
Unobservable Inputs (Level 3) | June 2030 Notes | Fair Value    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Approximate Fair Value 0 352,274
Unobservable Inputs (Level 3) | March 2026 A Notes | Fair Value    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Approximate Fair Value   50,615
Unobservable Inputs (Level 3) | March 2026 B Notes | Fair Value    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Approximate Fair Value   50,627
Unobservable Inputs (Level 3) | 2031 Asset-Backed Notes | Fair Value    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Approximate Fair Value 0 0
Unobservable Inputs (Level 3) | 2033 Notes | Fair Value    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Approximate Fair Value 0 0
Unobservable Inputs (Level 3) | MUFG Bank Facility | Fair Value    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Approximate Fair Value 220,000 168,000
Unobservable Inputs (Level 3) | SMBC Facility | Fair Value    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Approximate Fair Value $ 282,307 $ 277,934