Quarterly report pursuant to Section 13 or 15(d)

FAIR VALUE HIERARCHY FOR INVESTMENTS???PORTFOLIO COMPOSITION - Schedule of Changes in Fair Value of Level??3 Portfolio Investments (Details)

v3.23.3
FAIR VALUE HIERARCHY FOR INVESTMENTS—PORTFOLIO COMPOSITION - Schedule of Changes in Fair Value of Level 3 Portfolio Investments (Details) - USD ($)
$ in Thousands
 9 Months Ended
Sep. 30, 2023
Sep. 30, 2022
Investments    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]    
Beginning balance $ 4,100,273 $ 3,559,837
Transfers Into Level 3 Hierarchy 0 0
Redemptions/ Repayments (577,061) (486,293)
New Investments 604,892 916,689
Other (223) 0
Ending balance 4,294,722 3,971,635
Investments | Net Changes from Unrealized to Realized    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]    
Gain (loss) included in earnings 103,670 (2,784)
Investments | Net Unrealized Appreciation (Depreciation)    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]    
Gain (loss) included in earnings 63,171 (15,815)
Debt    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]    
Beginning balance 2,928,196 2,509,568
Transfers Into Level 3 Hierarchy 0 0
Redemptions/ Repayments (536,800) (436,372)
New Investments 547,102 869,214
Other (29,969) (6,933)
Ending balance 2,982,936 2,866,399
Debt | Net Changes from Unrealized to Realized    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]    
Gain (loss) included in earnings 101,276 9,632
Debt | Net Unrealized Appreciation (Depreciation)    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]    
Gain (loss) included in earnings (26,869) (78,710)
Equity    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]    
Beginning balance 1,166,643 1,043,709
Transfers Into Level 3 Hierarchy 0 0
Redemptions/ Repayments (40,261) (49,447)
New Investments 55,699 47,475
Other 32,322 6,933
Ending balance 1,304,876 1,100,460
Equity | Net Changes from Unrealized to Realized    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]    
Gain (loss) included in earnings 2,394 (11,801)
Equity | Net Unrealized Appreciation (Depreciation)    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]    
Gain (loss) included in earnings 88,079 63,591
Equity Warrant    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]    
Beginning balance 5,434 6,560
Transfers Into Level 3 Hierarchy 0 0
Redemptions/ Repayments 0 (474)
New Investments 2,091 0
Other (2,576) 0
Ending balance 6,910 4,775
Equity Warrant | Net Changes from Unrealized to Realized    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]    
Gain (loss) included in earnings 0 (615)
Equity Warrant | Net Unrealized Appreciation (Depreciation)    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]    
Gain (loss) included in earnings $ 1,961 $ (696)