Borrowings - Narrative (Details) - USD ($)						3 Months Ended
	Nov. 21, 2023	Sep. 29, 2023	Jun. 28, 2023	Feb. 24, 2023	May 25, 2022	Dec. 31, 2023	Dec. 31, 2022	Nov. 14, 2023	Sep. 30, 2023	Aug. 15, 2023	Jul. 05, 2023	Oct. 06, 2022	May 24, 2022
Line of Credit Facility [Line Items]
Borrowings outstanding						$ 570,000,000			$ 445,000,000
Derivative interest rate								8.40%
Notional amount								$ 350,000,000
Secured Overnight Financing Rate (SOFR)
Line of Credit Facility [Line Items]
Floating interest rate								4.0405%
Line of Credit | ING Credit Agreement
Line of Credit Facility [Line Items]
Aggregate principal amount			$ 1,110,000,000		$ 450,000,000					$ 1,185,000,000		$ 490,000,000	$ 150,000,000
Availability period					4 years
Maturity date period					5 years
Increase in borrowing capacity										$ 75,000,000		$ 40,000,000
Unused capacity, commitment fee			0.375%		0.375%
Unused capacity, commitment fee, potential increase, percentage			1.00%
Line of credit facility, unused capacity, percentage threshold			65.00%
Accordion feature, increase limit					$ 1,250,000,000
Accordion feature, increase limit, percentage of shareholders' equity					150.00%
Borrowings outstanding						$ 420,000,000			$ 320,000,000
Weighted average interest rate						7.69%	5.81%
Interest expense inclusive of fees						$ 9,317,000	$ 2,806,000
Line of Credit | ING Credit Agreement | Secured Overnight Financing Rate (SOFR)
Line of Credit Facility [Line Items]
Debt instrument, basis spread, variable rate			2.15%		1.875%
Line of Credit | ING Credit Agreement | Secured Overnight Financing Rate (SOFR) | External Credit Rating, Investment Grade
Line of Credit Facility [Line Items]
Debt instrument, basis spread, variable rate			2.05%
Line of Credit | ING Credit Agreement | Base Rate
Line of Credit Facility [Line Items]
Debt instrument, basis spread, variable rate			1.15%		0.875%
Line of Credit | ING Credit Agreement | Base Rate | External Credit Rating, Investment Grade
Line of Credit Facility [Line Items]
Debt instrument, basis spread, variable rate			1.05%
Line of Credit | ING Credit Agreement | Federal Funds Effective Rate
Line of Credit Facility [Line Items]
Debt instrument, basis spread, variable rate			0.50%		0.50%
Line of Credit | ING Credit Agreement | Overnight Bank Funding Rate
Line of Credit Facility [Line Items]
Debt instrument, basis spread, variable rate			0.50%		0.50%
Line of Credit | ING Credit Agreement Amendment
Line of Credit Facility [Line Items]
Aggregate principal amount			$ 1,110,000,000
Availability period			4 years
Maturity date period			5 years
Line of Credit | JPM SPV Facility
Line of Credit Facility [Line Items]
Aggregate principal amount				$ 150,000,000							$ 300,000,000
Maturity date period				5 years
Accordion feature, increase limit				$ 500,000,000
Borrowings outstanding						$ 150,000,000
Weighted average interest rate						8.49%
Interest expense inclusive of fees						$ 3,592,000
Reinvestment period				3 years
Tenor				3 months
Line of Credit | JPM SPV Facility | Secured Overnight Financing Rate (SOFR)
Line of Credit Facility [Line Items]
Debt instrument, basis spread, variable rate				2.95%
Line of Credit | SMBC SPV Facility
Line of Credit Facility [Line Items]
Aggregate principal amount		$ 150,000,000
Availability period		3 years
Unused capacity, commitment fee		0.50%
Line of credit facility, unused capacity, percentage threshold		0.50%
Borrowings outstanding						0
Interest expense inclusive of fees						287,000
Term		5 years
Interest rate		0.75%
Line of Credit | SMBC SPV Facility | Secured Overnight Financing Rate (SOFR) | Interest Rate Scenario One | Minimum
Line of Credit Facility [Line Items]
Debt instrument, basis spread, variable rate		2.45%
Line of Credit | SMBC SPV Facility | Secured Overnight Financing Rate (SOFR) | Interest Rate Scenario Two
Line of Credit Facility [Line Items]
Debt instrument, basis spread, variable rate		1.00%
Line of Credit | SMBC SPV Facility | Secured Overnight Financing Rate (SOFR) | Interest Rate Scenario Two | Minimum
Line of Credit Facility [Line Items]
Debt instrument, additional basis spread, variable rate		1.45%
Line of Credit | SMBC SPV Facility | Secured Overnight Financing Rate (SOFR) | Collateral Credit Facility | Interest Rate Scenario One | Maximum
Line of Credit Facility [Line Items]
Debt instrument, basis spread, variable rate		3.00%
Line of Credit | SMBC SPV Facility | Secured Overnight Financing Rate (SOFR) | Collateral Credit Facility | Interest Rate Scenario Two | Maximum
Line of Credit Facility [Line Items]
Debt instrument, additional basis spread, variable rate		2.00%
Line of Credit | SMBC SPV Facility | Base Rate | Interest Rate Scenario Two
Line of Credit Facility [Line Items]
Debt instrument, basis spread, variable rate	0.00%	0.00%
Line of Credit | SMBC SPV Facility | Federal Funds Effective Rate
Line of Credit Facility [Line Items]
Debt instrument, basis spread, variable rate		50.00%
Line of Credit | CIBC Loan and Servicing Agreement
Line of Credit Facility [Line Items]
Aggregate principal amount	$ 150,000,000
Unused capacity, commitment fee	0.50%
Accordion feature, increase limit	$ 500,000,000
Interest expense inclusive of fees						$ 75,000
Reinvestment period	2 years
Term	2 years
Applicable spread increase after stated maturity date or event of default	2.00%
Line of Credit | CIBC Loan and Servicing Agreement | Interest Rate Scenario Two
Line of Credit Facility [Line Items]
Debt instrument, additional basis spread, variable rate	0.95%
Line of Credit | CIBC Loan and Servicing Agreement | Secured Overnight Financing Rate (SOFR) | Interest Rate Scenario One
Line of Credit Facility [Line Items]
Debt instrument, basis spread, variable rate	1.95%
Line of Credit | CIBC Loan and Servicing Agreement | Secured Overnight Financing Rate (SOFR) | Interest Rate Scenario Two
Line of Credit Facility [Line Items]
Debt instrument, basis spread, variable rate	1.00%
Line of Credit | CIBC Loan and Servicing Agreement | Federal Funds Effective Rate
Line of Credit Facility [Line Items]
Debt instrument, basis spread, variable rate	0.50%
Letter of Credit | ING Credit Agreement
Line of Credit Facility [Line Items]
Aggregate principal amount					$ 25,000,000
Letter of Credit | ING Credit Agreement Amendment
Line of Credit Facility [Line Items]
Aggregate principal amount			$ 25,000,000
Unsecured Notes | Notes due 2028
Line of Credit Facility [Line Items]
Principal amount								$ 350,000,000
Debt interest rate								8.40%