Quarterly report [Sections 13 or 15(d)]

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

v3.25.2
Fair Value of Financial Instruments - Schedule of Fair Value Hierarchy of Outstanding Borrowings (Details) - USD ($)
$ in Thousands
Jun. 30, 2025
Dec. 31, 2024
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Carrying value $ 2,064,166 $ 1,768,955
Carrying Value    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Carrying value 2,064,166 1,768,955
Carrying Value | SBA Debentures    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Carrying value 340,422 271,371
Carrying Value | February 2025 Notes    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Carrying value   49,981
Carrying Value | June 2025 Notes    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Carrying value   69,919
Carrying Value | June 2025 3-Year Notes    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Carrying value   49,926
Carrying Value | March 2026 A Notes    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Carrying value 49,937 49,889
Carrying Value | March 2026 B Notes    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Carrying value 49,931 49,880
Carrying Value | September 2026 Notes    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Carrying value 323,812 323,321
Carrying Value | January 2027 Notes    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Carrying value 347,930 347,265
Carrying Value | 2028 Convertible Notes    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Carrying value 279,099  
Carrying Value | June 2030 Notes    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Carrying value 341,827  
Carrying Value | 2031 Asset-Backed Notes    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Carrying value 111,150 118,769
Carrying Value | 2033 Notes    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Carrying value 39,097 39,043
Carrying Value | MUFG Bank Facility    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Carrying value 66,000 116,000
Carrying Value | SMBC Facility    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Carrying value 114,961 283,591
Fair Value    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Approximate Fair Value 2,040,731 1,713,360
Fair Value | Observable Inputs (Level 2)    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Approximate Fair Value 427,337 155,303
Fair Value | Unobservable Inputs (Level 3)    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Approximate Fair Value 1,613,394 1,558,057
Fair Value | SBA Debentures    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Approximate Fair Value 325,469 260,436
Fair Value | SBA Debentures | Unobservable Inputs (Level 3)    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Approximate Fair Value 325,469 260,436
Fair Value | February 2025 Notes    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Approximate Fair Value   50,698
Fair Value | February 2025 Notes | Unobservable Inputs (Level 3)    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Approximate Fair Value   50,698
Fair Value | June 2025 Notes    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Approximate Fair Value   69,308
Fair Value | June 2025 Notes | Unobservable Inputs (Level 3)    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Approximate Fair Value   69,308
Fair Value | June 2025 3-Year Notes    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Approximate Fair Value   49,713
Fair Value | June 2025 3-Year Notes | Unobservable Inputs (Level 3)    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Approximate Fair Value   49,713
Fair Value | March 2026 A Notes    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Approximate Fair Value 50,221 49,052
Fair Value | March 2026 A Notes | Unobservable Inputs (Level 3)    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Approximate Fair Value 50,221 49,052
Fair Value | March 2026 B Notes    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Approximate Fair Value 50,245 49,087
Fair Value | March 2026 B Notes | Unobservable Inputs (Level 3)    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Approximate Fair Value 50,245 49,087
Fair Value | September 2026 Notes    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Approximate Fair Value 314,629 302,244
Fair Value | September 2026 Notes | Unobservable Inputs (Level 3)    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Approximate Fair Value 314,629 302,244
Fair Value | January 2027 Notes    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Approximate Fair Value 341,529 327,928
Fair Value | January 2027 Notes | Unobservable Inputs (Level 3)    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Approximate Fair Value 341,529 327,928
Fair Value | 2028 Convertible Notes    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Approximate Fair Value 278,784  
Fair Value | 2028 Convertible Notes | Observable Inputs (Level 2)    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Approximate Fair Value 278,784  
Fair Value | June 2030 Notes    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Approximate Fair Value 350,166  
Fair Value | June 2030 Notes | Unobservable Inputs (Level 3)    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Approximate Fair Value 350,166  
Fair Value | 2031 Asset-Backed Notes    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Approximate Fair Value 108,505 115,031
Fair Value | 2031 Asset-Backed Notes | Observable Inputs (Level 2)    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Approximate Fair Value 108,505 115,031
Fair Value | 2033 Notes    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Approximate Fair Value 40,048 40,272
Fair Value | 2033 Notes | Observable Inputs (Level 2)    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Approximate Fair Value 40,048 40,272
Fair Value | MUFG Bank Facility    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Approximate Fair Value 66,000 116,000
Fair Value | MUFG Bank Facility | Unobservable Inputs (Level 3)    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Approximate Fair Value 66,000 116,000
Fair Value | SMBC Facility    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Approximate Fair Value 115,135 283,591
Fair Value | SMBC Facility | Unobservable Inputs (Level 3)    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Approximate Fair Value $ 115,135 $ 283,591