In millions, except per share items | Jun-30-23 | Sep-30-22 | Jun-30-22 | Mar-31-22 | Dec-31-21 | Sep-30-21 | Jun-30-21 | Mar-31-21 |
| 10-Q | 8-K | 10-Q | 10-Q | 10-K | 10-Q | 10-Q | 10-Q |
Investment Income, Net [Abstract] | | | | | | | | |
Interest and Other Income [Abstract] | | | | | | | | |
Investment Income, Interest | 34.5 | | 27.0 | | | | | |
Fee Income | 0.1 | | | | | | | |
Noninterest Income | -39.1 | | -26.6 | 1.4 | 0.3 | 2.3 | 0.6 | 0.5 |
Gross Investment Income, Operating | 35.2 | | 27.4 | | | | | |
|
Operating Expenses [Abstract] | | | | | | | | |
Base management fee | 4.5 | | 3.9 | | | | | |
Income incentive fee | | | 3.2 | | | | | |
Interest Expense, Debt | 9.9 | | 6.1 | | | | | |
Other Expenses | 0.6 | | 0.5 | | | | | |
General and Administrative Expense | 1.3 | 1.1 | 1.1 | 1.0 | 1.2 | 1.1 | 0.8 | 1.0 |
Operating Expenses | 16.3 | 1.1 | 14.8 | 13.8 | -29.2 | 11.3 | 10.9 | 11.1 |
Net Investment Income | 18.8 | 16.9 | 12.7 | 13.5 | 12.9 | 9.9 | 9.4 | 8.9 |
|
Realized and Unrealized Gain (Loss), Investment and Derivative, Operating, before Tax [Abstract] | | | | | | | | |
Realized Investment Gains (Losses) | -39.7 | | -27.1 | | | | | |
|
Unrealized Gain (Loss) on Investments | | | | | | | | |
Gain (Loss) on Extinguishment of Debt | | | | | | | | |
Gain (Loss) on Investments | -39.7 | | -27.1 | | | | | |
Net Income (Loss) | -20.9 | | -14.4 | | | | | |
Net Income (Loss) Attributable to Parent, Total | -20.9 | | -14.4 | | | | | |
|
Diluted net investment income per share of common stock (in dollars per share) | $0.53 | | $0.41 | | | | | |
Basic net investment income per share of common stock (in dollars per share) | $0.53 | | $0.41 | | | | | |
Net increase (decrease) in net assets resulting from operations per share of common stock | 0.0 | | 0.0 | | | | | |
|
Basic weighted average shares of common stock outstanding (in shares) | 35.4 | 33.4 | 31.0 | 31.0 | 30.9 | 31.0 | 30.9 | 30.9 |
Diluted weighted average shares of common stock outstanding (in shares) | 35.4 | 33.4 | 31.0 | 31.0 | 30.9 | 31.0 | 30.9 | 30.9 |
|
Regular Distributions Declared Per Share | | | | | | | | |
Special Distributions Declared, Per Share | | | | | | | | |
Earnings Per Share, Diluted, Distributed | | | 0.0 | | | | | |
Earnings Per Share, Basic, Distributed | 0.0 | | 0.0 | | | | | |