Quarterly report pursuant to Section 13 or 15(d)

DEBT - Summary of Debt (Details)

v3.22.2.2
DEBT - Summary of Debt (Details) - USD ($)
$ in Thousands
Sep. 30, 2022
Dec. 31, 2021
Jan. 31, 2021
Apr. 30, 2019
Nov. 30, 2017
Debt Instrument [Line Items]          
Outstanding Balance $ 2,046,000 $ 1,805,000      
Unamortized Debt Issuance (Costs)/ Premiums (7,616) (8,944)      
Recorded Value 2,038,384 1,796,056      
Estimated Fair Value 1,901,194 1,821,301      
Line of Credit          
Debt Instrument [Line Items]          
Recorded Value $ 561,000 320,000      
3.00% Notes due 2026          
Debt Instrument [Line Items]          
Debt instrument, interest rate, stated percentage 3.00%        
3.00% Notes due 2026 | Unsecured Notes          
Debt Instrument [Line Items]          
Outstanding Balance $ 500,000 500,000      
Unamortized Debt Issuance (Costs)/ Premiums (1,996) (2,391)      
Recorded Value 498,004 497,609      
Estimated Fair Value $ 422,715 $ 502,285      
Debt instrument, interest rate, stated percentage 3.00% 3.00% 3.00%    
5.20% Notes due 2024 | Unsecured Notes          
Debt Instrument [Line Items]          
Outstanding Balance $ 450,000 $ 450,000      
Unamortized Debt Issuance (Costs)/ Premiums 863 1,272      
Recorded Value 450,863 451,272      
Estimated Fair Value $ 444,114 $ 480,767      
Debt instrument, interest rate, stated percentage 5.20% 5.20%   5.20%  
SBIC Debentures | Unsecured Notes          
Debt Instrument [Line Items]          
Outstanding Balance $ 350,000 $ 350,000      
Unamortized Debt Issuance (Costs)/ Premiums (6,382) (7,269)      
Recorded Value 343,618 342,731      
Estimated Fair Value 288,546 328,206      
4.50% Notes due 2022 | Unsecured Notes          
Debt Instrument [Line Items]          
Outstanding Balance 185,000 185,000      
Unamortized Debt Issuance (Costs)/ Premiums (101) (556)      
Recorded Value 184,899 184,444      
Estimated Fair Value $ 184,819 $ 190,043      
Debt instrument, interest rate, stated percentage 4.50% 4.50%     4.50%
Credit Facility | Line of Credit          
Debt Instrument [Line Items]          
Outstanding Balance $ 561,000 $ 320,000      
Unamortized Debt Issuance (Costs)/ Premiums 0 0      
Recorded Value 561,000 320,000      
Estimated Fair Value $ 561,000 $ 320,000