Annual report pursuant to Section 13 and 15(d)

DEBT - Schedule of Debt (Details)

v3.24.0.1
DEBT - Schedule of Debt (Details) - USD ($)
Dec. 31, 2023
Dec. 31, 2022
Debt Instrument [Line Items]    
Outstanding Balance $ 1,810,000,000 $ 2,007,000,000
Unamortized Debt Issuance (Costs)/ Premiums (7,656,000) (7,898,000)
Recorded Value 1,802,344,000 1,999,102,000
Estimated Fair Value 1,704,974,000 1,882,810,000
Line of Credit | Revolving Credit Facility    
Debt Instrument [Line Items]    
Recorded Value 360,000,000 607,000,000
Line of Credit | Revolving Credit Facility | Corporate Facility    
Debt Instrument [Line Items]    
Outstanding Balance 200,000,000 407,000,000
Unamortized Debt Issuance (Costs)/ Premiums 0 0
Recorded Value 200,000,000 407,000,000
Estimated Fair Value 200,000,000 407,000,000
Line of Credit | Revolving Credit Facility | SPV Facility    
Debt Instrument [Line Items]    
Outstanding Balance 160,000,000 200,000,000
Unamortized Debt Issuance (Costs)/ Premiums 0 0
Recorded Value 160,000,000 200,000,000
Estimated Fair Value 160,000,000 200,000,000
Line of Credit | Revolving Credit Facility | July 2026 Notes    
Debt Instrument [Line Items]    
Outstanding Balance 500,000,000  
Unsecured Notes | Corporate Facility    
Debt Instrument [Line Items]    
Outstanding Balance 200,000,000  
Unsecured Notes | July 2026 Notes    
Debt Instrument [Line Items]    
Outstanding Balance 500,000,000 500,000,000
Unamortized Debt Issuance (Costs)/ Premiums (1,338,000) (1,864,000)
Recorded Value 498,662,000 498,136,000
Estimated Fair Value 458,105,000 434,250,000
Unsecured Notes | May 2024 Notes    
Debt Instrument [Line Items]    
Outstanding Balance 450,000,000 450,000,000
Unamortized Debt Issuance (Costs)/ Premiums 182,000 727,000
Recorded Value 450,182,000 450,727,000
Estimated Fair Value 447,246,000 444,749,000
Unsecured Notes | SBIC Debentures    
Debt Instrument [Line Items]    
Outstanding Balance 350,000,000 350,000,000
Unamortized Debt Issuance (Costs)/ Premiums (5,465,000) (6,086,000)
Recorded Value 344,535,000 343,914,000
Estimated Fair Value 288,468,000 290,204,000
Unsecured Notes | December 2025 Notes    
Debt Instrument [Line Items]    
Outstanding Balance 150,000,000 100,000,000
Unamortized Debt Issuance (Costs)/ Premiums (1,035,000) (675,000)
Recorded Value 148,965,000 99,325,000
Estimated Fair Value $ 151,155,000 $ 106,607,000