Quarterly report [Sections 13 or 15(d)]

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

v3.25.1
Fair Value of Financial Instruments - Schedule of Fair Value Hierarchy of Outstanding Borrowings (Details) - USD ($)
$ in Thousands
Mar. 31, 2025
Dec. 31, 2024
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Carrying value $ 1,976,623 $ 1,768,955
Carrying Value    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Carrying value 1,976,623 1,768,955
Carrying Value | SBA Debentures    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Carrying value 287,049 271,371
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 69,960 69,919
Carrying Value | June 2025 3-Year Notes    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Carrying value 49,965 49,926
Carrying Value | March 2026 A Notes    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Carrying value 49,913 49,889
Carrying Value | March 2026 B Notes    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Carrying value 49,905 49,880
Carrying Value | September 2026 Notes    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Carrying value 323,566 323,321
Carrying Value | January 2027 Notes    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Carrying value 347,598 347,265
Carrying Value | 2028 Convertible Notes    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Carrying value 278,503  
Carrying Value | 2031 Asset-Backed Notes    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Carrying value 116,272 118,769
Carrying Value | 2033 Notes    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Carrying value 39,070 39,043
Carrying Value | MUFG Bank Facility    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Carrying value 105,000 116,000
Carrying Value | SMBC Facility    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Carrying value 259,822 283,591
Fair Value    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Approximate Fair Value 1,924,296 1,713,360
Fair Value | Observable Inputs (Level 2)    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Approximate Fair Value 435,910 155,303
Fair Value | Unobservable Inputs (Level 3)    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Approximate Fair Value 1,488,386 1,558,057
Fair Value | SBA Debentures    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Approximate Fair Value 268,236 260,436
Fair Value | SBA Debentures | Unobservable Inputs (Level 3)    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Approximate Fair Value 268,236 260,436
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 70,637 69,308
Fair Value | June 2025 Notes | Unobservable Inputs (Level 3)    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Approximate Fair Value 70,637 69,308
Fair Value | June 2025 3-Year Notes    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Approximate Fair Value 50,678 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 50,678 49,713
Fair Value | March 2026 A Notes    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Approximate Fair Value 49,012 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 49,012 49,052
Fair Value | March 2026 B Notes    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Approximate Fair Value 49,036 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 49,036 49,087
Fair Value | September 2026 Notes    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Approximate Fair Value 305,377 302,244
Fair Value | September 2026 Notes | Unobservable Inputs (Level 3)    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Approximate Fair Value 305,377 302,244
Fair Value | January 2027 Notes    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Approximate Fair Value 330,404 327,928
Fair Value | January 2027 Notes | Unobservable Inputs (Level 3)    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Approximate Fair Value 330,404 327,928
Fair Value | 2028 Convertible Notes    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Approximate Fair Value 282,109  
Fair Value | 2028 Convertible Notes | Observable Inputs (Level 2)    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Approximate Fair Value 282,109  
Fair Value | 2031 Asset-Backed Notes    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Approximate Fair Value 113,433 115,031
Fair Value | 2031 Asset-Backed Notes | Observable Inputs (Level 2)    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Approximate Fair Value 113,433 115,031
Fair Value | 2033 Notes    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Approximate Fair Value 40,368 40,272
Fair Value | 2033 Notes | Observable Inputs (Level 2)    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Approximate Fair Value 40,368 40,272
Fair Value | MUFG Bank Facility    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Approximate Fair Value 105,000 116,000
Fair Value | MUFG Bank Facility | Unobservable Inputs (Level 3)    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Approximate Fair Value 105,000 116,000
Fair Value | SMBC Facility    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Approximate Fair Value 260,006 283,591
Fair Value | SMBC Facility | Unobservable Inputs (Level 3)    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Approximate Fair Value $ 260,006 $ 283,591