FAIR VALUE MEASUREMENTS - Level III Rollforward (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair value, beginning of period	$ 3,117,354	$ 2,828,035
Purchases of investments	1,231,397	620,812
Proceeds from principal repayments and sales of investments	(655,418)	(359,835)
Accretion of discount/amortization of premium	14,615	11,187
Payment-in-kind	13,073	6,069
Transfers into/(out) of Level 3	(27,476)	(26,924)
Fair value, end of period	3,686,956	3,117,354
Net change in unrealized appreciation (depreciation) from investments still held	2,109	37,840
Net change in unrealized appreciation (depreciation)
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Total gains or losses included in earnings	$ 9,891	$ 37,892
Fair Value, Asset, Recurring Basis, Still Held, Unrealized Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]	Net change in unrealized appreciation (depreciation) on non-controlled/non-affiliated investments	Net change in unrealized appreciation (depreciation) on non-controlled/non-affiliated investments
Fair Value, Asset, Recurring Basis, Unobservable Input Reconciliation, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]	Net change in unrealized appreciation (depreciation) on non-controlled/non-affiliated investments	Net change in unrealized appreciation (depreciation) on non-controlled/non-affiliated investments
Net realized gains (losses)
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Total gains or losses included in earnings	$ (16,480)	$ 118
Fair Value, Asset, Recurring Basis, Unobservable Input Reconciliation, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]	Net realized gain (loss) on non-controlled/non-affiliated investments	Net realized gain (loss) on non-controlled/non-affiliated investments
First Lien Debt
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair value, beginning of period	$ 2,979,870	$ 2,668,749
Purchases of investments	1,220,903	618,914
Proceeds from principal repayments and sales of investments	(594,707)	(359,835)
Accretion of discount/amortization of premium	13,762	10,908
Payment-in-kind	9,091	3,417
Transfers into/(out) of Level 3	(27,476)	0
Fair value, end of period	3,603,209	2,979,870
Net change in unrealized appreciation (depreciation) from investments still held	4,259	37,547
First Lien Debt | Net change in unrealized appreciation (depreciation)
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Total gains or losses included in earnings	7,497	37,599
First Lien Debt | Net realized gains (losses)
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Total gains or losses included in earnings	(5,731)	118
Second Lien Debt
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair value, beginning of period	96,848	122,891
Purchases of investments	836	86
Proceeds from principal repayments and sales of investments	(59,230)	0
Accretion of discount/amortization of premium	837	269
Payment-in-kind	842	532
Transfers into/(out) of Level 3	0	(26,924)
Fair value, end of period	33,351	96,848
Net change in unrealized appreciation (depreciation) from investments still held	(1,256)	(6)
Second Lien Debt | Net change in unrealized appreciation (depreciation)
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Total gains or losses included in earnings	3,723	(6)
Second Lien Debt | Net realized gains (losses)
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Total gains or losses included in earnings	(10,505)	0
Other Debt Investments
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair value, beginning of period	2,064
Purchases of investments	5,770
Proceeds from principal repayments and sales of investments	0
Accretion of discount/amortization of premium	16
Payment-in-kind	560
Transfers into/(out) of Level 3	0
Fair value, end of period	9,198	2,064
Net change in unrealized appreciation (depreciation) from investments still held	788
Other Debt Investments | Net change in unrealized appreciation (depreciation)
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Total gains or losses included in earnings	788
Other Debt Investments | Net realized gains (losses)
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Total gains or losses included in earnings	0
Equity
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair value, beginning of period	38,572
Purchases of investments	3,888
Proceeds from principal repayments and sales of investments	(1,481)
Accretion of discount/amortization of premium	0
Payment-in-kind	2,580
Transfers into/(out) of Level 3	0
Fair value, end of period	41,198	38,572
Net change in unrealized appreciation (depreciation) from investments still held	(1,682)
Equity | Net change in unrealized appreciation (depreciation)
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Total gains or losses included in earnings	(2,117)
Equity | Net realized gains (losses)
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Total gains or losses included in earnings	(244)
Other Securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair value, beginning of period	$ 40,636	36,395
Purchases of investments		1,812
Proceeds from principal repayments and sales of investments		0
Accretion of discount/amortization of premium		10
Payment-in-kind		2,120
Transfers into/(out) of Level 3		0
Fair value, end of period		40,636
Net change in unrealized appreciation (depreciation) from investments still held		299
Other Securities | Net change in unrealized appreciation (depreciation)
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Total gains or losses included in earnings		299
Other Securities | Net realized gains (losses)
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Total gains or losses included in earnings		$ 0