Debt - Outstanding borrowings (Details) - USD ($) $ in Thousands |
Mar. 31, 2026 |
Jan. 29, 2026 |
Dec. 31, 2025 |
Feb. 06, 2025 |
Nov. 30, 2021 |
Oct. 13, 2021 |
Mar. 10, 2021 |
Aug. 28, 2019 |
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|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Debt | ||||||||||||||
| Total aggregate principal amount committed | $ 2,127,000 | $ 2,077,000 | ||||||||||||
| Principal amount outstanding | 1,467,000 | 1,473,000 | ||||||||||||
| Carrying value | [1] | 1,454,657 | 1,470,796 | |||||||||||
| 2019-1 Notes | ||||||||||||||
| Debt | ||||||||||||||
| Total aggregate principal amount committed | 272,000 | 272,000 | $ 410,000 | $ 501,000 | ||||||||||
| Principal amount outstanding | 272,000 | 272,000 | ||||||||||||
| Carrying value | [1] | 270,265 | 270,224 | |||||||||||
| March 2026 Notes | ||||||||||||||
| Debt | ||||||||||||||
| Total aggregate principal amount committed | 0 | 300,000 | $ 300,000 | |||||||||||
| Principal amount outstanding | 0 | 300,000 | ||||||||||||
| Carrying value | [1] | 0 | 299,786 | |||||||||||
| October 2026 Notes | ||||||||||||||
| Debt | ||||||||||||||
| Total aggregate principal amount committed | 300,000 | 300,000 | $ 300,000 | |||||||||||
| Principal amount outstanding | 300,000 | 300,000 | ||||||||||||
| Carrying value | [1] | 299,264 | 298,926 | |||||||||||
| March 2030 Notes | ||||||||||||||
| Debt | ||||||||||||||
| Total aggregate principal amount committed | 350,000 | [2] | 350,000 | [2] | $ 350,000 | |||||||||
| Principal amount outstanding | [2] | 350,000 | 350,000 | |||||||||||
| Carrying value | [1],[2] | 348,530 | 350,860 | |||||||||||
| March 2031 Notes | ||||||||||||||
| Debt | ||||||||||||||
| Total aggregate principal amount committed | 350,000 | [2] | $ 350,000 | 0 | [2] | |||||||||
| Principal amount outstanding | [2] | 350,000 | 0 | |||||||||||
| Carrying value | [1],[2] | 341,598 | 0 | |||||||||||
| Sumitomo Credit Facility | ||||||||||||||
| Debt | ||||||||||||||
| Total aggregate principal amount committed | 855,000 | 855,000 | ||||||||||||
| Principal amount outstanding | 195,000 | 251,000 | ||||||||||||
| Carrying value | [1] | $ 195,000 | $ 251,000 | |||||||||||
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