v3.25.4

BORROWINGS - Narrative (Details)								1 Months Ended	3 Months Ended		9 Months Ended
	Oct. 13, 2025 USD ($)	Dec. 09, 2024 USD ($)	Nov. 04, 2024 USD ($) trading_day $ / shares	Mar. 20, 2024 USD ($)	Mar. 01, 2024	Aug. 02, 2023 USD ($)	Apr. 20, 2021 USD ($)	Aug. 31, 2021 USD ($)	Dec. 31, 2025 USD ($) lender facility $ / shares	Dec. 31, 2024 USD ($)	Dec. 31, 2025 USD ($) lender facility consecutive_trading_day $ / shares	Dec. 31, 2024 USD ($)	Sep. 30, 2025 USD ($)	Mar. 31, 2025 USD ($)	Jun. 20, 2024 USD ($)	Jun. 19, 2024 USD ($)	Aug. 01, 2023 USD ($)	Jun. 30, 2023 USD ($)	Nov. 30, 2021 USD ($)	Feb. 28, 2021 USD ($)	Dec. 31, 2020 USD ($)	Apr. 25, 2019
Debt Instrument [Line Items]
Asset coverage ratio																						166.00%
Current asset coverage ratio									211.00%		211.00%
Leverage commitment amount drawn									$ 1,089,000,000		$ 1,089,000,000			$ 969,875,000
January 2026 Notes | Notes
Debt Instrument [Line Items]
Weighted average interest rate									0.00%	4.46%	0.00%	4.46%
Aggregate principal amount																				$ 65,000,000	$ 75,000,000
Fixed interest rate																					4.50%
Issuance price percent received																				102.11%
Yield-to-maturity																				4.00%
Repurchased face amount		$ 140,000,000
Redemption price, percentage		100.00%
Realized loss on disposal of fixed assets										$ 400,000
October 2026 Notes | Notes
Debt Instrument [Line Items]
Weighted average interest rate									3.50%	3.50%	3.50%	3.50%
Aggregate principal amount								$ 100,000,000											$ 50,000,000
Fixed interest rate								3.375%											3.375%
Issuance price percent received								99.418%											99.993%
Yield-to-maturity								3.50%											3.375%
Repurchased face amount	$ 150,000,000
Redemption price, percentage	100.00%
Realized loss on disposal of fixed assets									$ 800,000
Leverage commitment amount drawn														150,000,000
October 2026 Notes | Convertible Debt
Debt Instrument [Line Items]
Fixed interest rate			5.125%
August 2028 Notes | Notes
Debt Instrument [Line Items]
Weighted average interest rate									7.75%	7.75%	7.75%	7.75%
Aggregate principal amount																		$ 71,900,000
Fixed interest rate																		7.75%
Repurchased face amount	$ 71,900,000
Redemption price, percentage	100.00%
Realized loss on disposal of fixed assets									$ 1,400,000
Leverage commitment amount drawn														71,875,000
August 2028 Notes Overallotment | Notes
Debt Instrument [Line Items]
Aggregate principal amount																		$ 9,400,000
2029 Convertible Notes | Convertible Debt
Debt Instrument [Line Items]
Weighted average interest rate									5.13%	5.13%	5.13%	5.13%
Aggregate principal amount			$ 230,000,000
Fixed interest rate			5.125%
Redemption price, percentage											100.00%
Conversion rate			0.04								40.54
Conversion price (in usd per share) | $ / shares			$ 25.00						$ 24.67		$ 24.67
Dividend increase (in usd per share) | $ / shares									$ 0.58		$ 0.58
Percentage of stock price			130.00%
Trading days | trading_day			20
Consecutive trading days | consecutive_trading_day											30
Leverage commitment amount drawn									$ 230,000,000		$ 230,000,000			230,000,000
2029 Convertible Notes | Convertible Debt | Maximum
Debt Instrument [Line Items]
Conversion rate											0.0447828
2029 Convertible Notes Overallotement | Convertible Debt
Debt Instrument [Line Items]
Aggregate principal amount			$ 30,000,000
September 2030 Notes | Notes
Debt Instrument [Line Items]
Weighted average interest rate									5.95%	0.00%	5.95%	0.00%
Aggregate principal amount													$ 350,000,000
Fixed interest rate													5.95%
Issuance price percent received													99.345%
Yield-to-maturity													6.104%
Redemption price, percentage								100.00%
Leverage commitment amount drawn									$ 350,000,000		$ 350,000,000
SBA Debentures | Unsecured Debt
Debt Instrument [Line Items]
Weighted average interest rate									4.46%	4.40%	4.42%	4.39%
Leverage commitment amount drawn									$ 195,000,000		$ 195,000,000			175,000,000
SBA Debentures | Unsecured Debt | SBIC I
Debt Instrument [Line Items]
Maturity							10 years
Regulatory maximum borrowing capacity							$ 175,000,000
Regulatory capital							$ 87,500,000		87,500,000		87,500,000
Available leverage commitment									87,500,000		87,500,000
Leverage commitment amount drawn									175,000,000		175,000,000
Leverage commitment amount									175,000,000		175,000,000
SBA Debentures | Unsecured Debt | SBIC II
Debt Instrument [Line Items]
Regulatory capital									87,500,000		87,500,000
Available leverage commitment									46,000,000		46,000,000
Leverage commitment amount drawn									20,000,000		20,000,000
Leverage commitment amount									$ 40,000,000		$ 40,000,000
Corporate Credit Facility | Line of Credit
Debt Instrument [Line Items]
Weighted average interest rate									6.44%		6.63%
Average borrowings									$ 315,000,000		$ 316,700,000
Corporate Credit Facility | Corporate Credit Facility | Line of Credit
Debt Instrument [Line Items]
Number of revolving credit facility | facility									1		1
Weighted average interest rate									6.39%	7.19%	6.56%	7.53%
Average borrowings									$ 206,522,000	$ 179,511,000	$ 205,727,000	$ 134,665,000
Basis spread on variable rate						2.15%
Maximum borrowing capacity						$ 435,000,000			$ 510,000,000		$ 510,000,000						$ 400,000,000
Accordion feature increase limit						$ 750,000,000
Number of lenders | lender									11		11
Minimum senior coverage ratio					2.00
Maximum asset coverage ratio					1.50
Interest coverage ratio					2.00
Leverage commitment amount drawn									$ 210,000,000		$ 210,000,000			235,000,000
Corporate Credit Facility | Corporate Credit Facility | Line of Credit | Minimum
Debt Instrument [Line Items]
Commitment fee percentage					0.50%
Corporate Credit Facility | Corporate Credit Facility | Line of Credit | Maximum
Debt Instrument [Line Items]
Commitment fee percentage					1.00%
SPV Credit Facility | SPV Credit Facility | Line of Credit
Debt Instrument [Line Items]
Number of revolving credit facility | facility									1		1
Weighted average interest rate									6.53%	7.23%	6.75%	7.54%
Average borrowings									$ 108,435,000	$ 104,435,000	$ 110,942,000	$ 55,664,000
Maximum borrowing capacity				$ 150,000,000												$ 150,000,000
Accordion feature increase limit															$ 200,000,000
Accordion feature that allows increases (up to)				$ 400,000,000
Leverage commitment amount drawn									$ 104,000,000		$ 104,000,000			$ 108,000,000
SPV Credit Facility | SPV Credit Facility | Line of Credit | Before March 20 2027
Debt Instrument [Line Items]
Basis spread on variable rate				2.50%
SPV Credit Facility | SPV Credit Facility | Line of Credit | After March 20 2027
Debt Instrument [Line Items]
Basis spread on variable rate				2.85%
SPV Credit Facility | SPV Credit Facility | Line of Credit | Before April 20 2024
Debt Instrument [Line Items]
Commitment fee percentage				0.10%
SPV Credit Facility | SPV Credit Facility | Line of Credit | After April 20 2024
Debt Instrument [Line Items]
Commitment fee percentage				0.35%

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