Financial Highlights - Schedule of Financial Highlights of the Company (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands |
3 Months Ended | 9 Months Ended | ||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Sep. 30, 2022 |
Sep. 30, 2021 |
Sep. 30, 2022 |
Sep. 30, 2021 |
Jun. 30, 2022 |
Dec. 31, 2021 |
Jun. 30, 2021 |
Dec. 31, 2020 |
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| Net investment income before investment gains and losses per common share: | ||||||||||||||||||||
| Net asset value at beginning of period | $ 11.22 | $ 11.26 | ||||||||||||||||||
| Net investment income before investment gains and losses per common share: Basic | $ 0.39 | $ 0.33 | 1.01 | 0.95 | ||||||||||||||||
| Total from investment operations | 0.31 | 1.47 | ||||||||||||||||||
| Investment Company, Issuance of Shares, Per Share | [1] | 0.31 | (0.11) | |||||||||||||||||
| Distributions of net investment income | [2] | (0.09) | ||||||||||||||||||
| Stock-based compensation expense included in investment income | [3] | 0.09 | 0.07 | |||||||||||||||||
| Net asset value at end of period | 10.47 | 11.54 | 10.47 | 11.54 | ||||||||||||||||
| Ratios and supplemental data (in thousands, except per share data): | ||||||||||||||||||||
| Per share market value at end of period | $ 11.58 | $ 16.61 | $ 11.58 | $ 16.61 | ||||||||||||||||
| Total return | [4] | (24.34%) | 23.05% | |||||||||||||||||
| Shares outstanding at end of period | 130,191 | 115,925 | 130,191 | 115,925 | ||||||||||||||||
| Basic | 127,484 | 114,805 | 123,379 | 114,590 | ||||||||||||||||
| Diluted | 129,334 | 116,239 | 124,767 | 115,550 | ||||||||||||||||
| Net assets at end of period | $ (1,362,718) | $ (1,337,532) | $ (1,362,718) | $ (1,337,532) | $ (1,327,740) | $ (1,308,547) | $ (1,356,358) | $ (1,291,704) | ||||||||||||
| Ratio of total expense to average net assets | [5] | 9.51% | 9.93% | |||||||||||||||||
| Ratio of net investment income before investment gains and losses to average net assets | [5] | 12.53% | 11.01% | |||||||||||||||||
| Investment Company, Portfolio Turnover | [6] | 14.12% | 33.14% | |||||||||||||||||
| Weighted average debt outstanding | $ 1,430,814 | $ 1,246,769 | ||||||||||||||||||
| Weighted average debt per common share | $ 11.60 | $ 10.88 | ||||||||||||||||||
| Realized | ||||||||||||||||||||
| Net investment income before investment gains and losses per common share: | ||||||||||||||||||||
| Net gain (loss) | 0.01 | 0.12 | ||||||||||||||||||
| Unrealized | ||||||||||||||||||||
| Net investment income before investment gains and losses per common share: | ||||||||||||||||||||
| Net gain (loss) | (0.71) | 0.40 | ||||||||||||||||||
| Capital Gains Member | ||||||||||||||||||||
| Net investment income before investment gains and losses per common share: | ||||||||||||||||||||
| Distributions of net investment income | [2] | (0.35) | ||||||||||||||||||
| Ordinary Income | ||||||||||||||||||||
| Net investment income before investment gains and losses per common share: | ||||||||||||||||||||
| Distributions of net investment income | [2] | $ (1.11) | $ (1.06) | |||||||||||||||||
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