Borrowings - Company's Outstanding Debt (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023	Sep. 15, 2023	Apr. 07, 2022
Borrowings
Total aggregate principal amount committed/ outstanding	$ 2,394,963	$ 1,587,138
Principal Amount Outstanding	1,885,869	1,247,946
Carrying Value	1,864,938	1,233,334
Unamortized Debt Issuance Costs	20,931	14,612
Revolving Credit Facility
Borrowings
Total aggregate principal amount committed/ outstanding	385,000	325,000
Principal Amount Outstanding	254,606	256,808
Carrying Value	251,319	253,579
Unamortized Debt Issuance Costs	3,287	3,229
SPV Credit Facility
Borrowings
Total aggregate principal amount committed/ outstanding	450,000	450,000
Principal Amount Outstanding	312,000	179,000
Carrying Value	308,380	178,098
Unamortized Debt Issuance Costs	3,620	902
SPV II Credit Facility
Borrowings
Total aggregate principal amount committed/ outstanding	214,113	120,288
Principal Amount Outstanding	214,113	120,288
Carrying Value	212,325	119,240
Unamortized Debt Issuance Costs	1,788	1,048
SPV III Credit Facility
Borrowings
Total aggregate principal amount committed/ outstanding	100,000
Principal Amount Outstanding	60,000
Carrying Value	58,624	0
Unamortized Debt Issuance Costs	1,376
SPV IV Credit Facility
Borrowings
Total aggregate principal amount committed/ outstanding	350,000
Principal Amount Outstanding	149,300
Carrying Value	145,800	0
Unamortized Debt Issuance Costs	3,500
2022 ABS
Borrowings
Total aggregate principal amount committed/ outstanding	306,000	306,000		$ 425,000
Principal Amount Outstanding	306,000	306,000
Carrying Value	303,786	300,810
Unamortized Debt Issuance Costs	2,214	5,190
2022 Class C Notes
Borrowings
Carrying Value	36,125	36,125
2022 Subordinated Notes
Borrowings
Carrying Value	81,182	82,875
2023 ABS
Borrowings
Total aggregate principal amount committed/ outstanding	185,850	185,850	$ 251,169
Principal Amount Outstanding	185,850	185,850
Carrying Value	184,377	183,840
Unamortized Debt Issuance Costs	1,473	2,010
2028 Notes
Borrowings
Total aggregate principal amount committed/ outstanding	200,000	200,000
Principal Amount Outstanding	200,000	200,000
Carrying Value	198,059	197,767
Unamortized Debt Issuance Costs	1,941	2,233
2029 Notes
Borrowings
Total aggregate principal amount committed/ outstanding	204,000
Principal Amount Outstanding	204,000
Carrying Value	202,268	0
Unamortized Debt Issuance Costs	1,732
2023 Subordinated Notes
Borrowings
Total aggregate principal amount committed/ outstanding			$ 65,319
Carrying Value	$ 65,319	$ 65,319