| In millions, except per share items | Jun-30-23 | Jun-05-23 | Sep-30-22 | Jun-30-22 | Jun-05-22 | Mar-31-22 | Dec-31-21 | Sep-30-21 |
| | 10-Q | 8-K | 10-Q | 10-Q | 8-K | 10-Q | 10-K | 10-Q |
| Operating activities | | | | | | | | |
| Net increase (decrease) in net assets resulting from operations | 16.3 | | 38.6 | 12.3 | | | 32.6 | 101.2 |
| |
| Adjustments to reconcile net increase (decrease) in net assets resulting from operations to net cash from (used in) operating activities: | | | | | | | | |
| Net realized (gain) loss | | | | 18.4 | | | | |
| Realized loss on extinguishment of debt | | | | | | | | 6.2 |
| Change in net unrealized (appreciation) depreciation of investments | | | | 10.7 | | | | |
| Net amortization of investment discounts and premiums | | | -8.0 | -5.5 | | | -1.9 | -8.0 |
| Amortization of original issue discount on debt | | | 0.1 | 0.1 | | | 0.2 | 1.0 |
| Interest and dividend income paid in kind | | | | -3.1 | | | | |
| Amortization of deferred debt issuance costs | | | 2.3 | 1.6 | | | 0.9 | 2.8 |
| Changes in assets and liabilities: | | | | | | | | |
| Purchase of investments | | | -46.2 | -100.7 | | -111.3 | -178.5 | -155.7 |
| Proceeds from disposition of investments | | | | 235.6 | | | | |
| Decrease (increase) in interest, dividends and fees receivable | | | | 0.7 | | | | |
| Decrease (increase) in receivable for investments sold | | | | 5.8 | | | | |
| Decrease (increase) in prepaid expenses and other assets | | | -0.9 | 0.2 | | | -0.6 | -0.4 |
| Increase (decrease) in payable for investments purchased | | | | -29.0 | | | | |
| Increase (decrease) in incentive fees payable | | | | 0.8 | | | | |
| Increase (decrease) in interest and debt related payables | | | -7.4 | -1.3 | | | 7.5 | -6.5 |
| Increase (decrease) in reimbursements due to the Advisor | | | | 0.4 | | | | |
| Increase (decrease) in management fees payable | | | | 0.0 | | | | |
| Increase (decrease) in accrued expenses and other liabilities | | | 0.2 | 0.4 | | | -0.3 | 0.0 |
| Net cash provided by (used in) operating activities | 5.3 | | 168.5 | 36.3 | | | -33.4 | -49.3 |
| |
| Financing activities | | | | | | | | |
| Draws on credit facilities | | | 462.0 | 400.4 | | | 171.7 | 743.8 |
| Repayments of credit facility draws | | | -352.2 | -232.2 | | | -137.8 | -767.7 |
| Payments of debt issuance costs | | | | | | | -0.2 | -4.2 |
| Dividends paid to shareholders | | | -52.0 | -34.7 | | | -17.3 | -52.0 |
| |
| Repurchase of shares | | | | | | | | |
| Repayment of convertible notes | | | -140.0 | -140.0 | | | | |
| |
| Repayment of unsecured notes | | | | | | | | |
| Proceeds from issuance of unsecured notes | | | | | | | | |
| Net cash provided by (used in) financing activities | | | -82.2 | -6.4 | | | 16.3 | 65.8 |
| Net increase (decrease) in cash and cash equivalents (including restricted cash) | | | | 29.9 | | | | |
| |
| Supplemental cash flow information | | | | | | | | |
| Interest payments | | | 33.3 | 17.9 | | | 0.7 | 32.8 |
| |
| Distributions Payable | | | | | | | | |