| In millions, except per share items | Jun-30-23 | Mar-31-23 | Dec-31-22 | Sep-30-22 | Jun-30-22 | Mar-31-22 | Dec-31-21 | Sep-30-21 |
| | 10-Q | 10-Q | 10-K | 10-Q | 10-Q | 10-Q | 10-K | 10-Q |
| Cash flows from operating activities | | | | | | | | |
| Net income (loss) | 41.9 | 48.7 | 15.2 | 22.6 | 16.0 | 22.6 | 26.3 | 9.4 |
| |
| Adjustments to reconcile net income to net cash from operating activities: | | | | | | | | |
| Depreciation | 10.3 | 10.4 | 10.5 | 10.4 | 10.5 | 10.4 | 10.5 | 10.5 |
| Amortization of deferred financing costs | 0.1 | 0.1 | 0.1 | 0.1 | 0.1 | 0.1 | 0.1 | 0.1 |
| Benefit for deferred income taxes | -0.2 | -1.1 | -1.8 | 1.5 | -3.2 | -6.8 | -10.5 | -11.8 |
| Change in fair value of equity securities | -2.2 | 3.7 | 8.3 | 7.8 | 8.0 | 3.2 | 0.9 | -4.2 |
| Change in fair value of derivative instruments | -1.2 | -3.7 | -0.3 | -4.6 | -2.9 | -0.2 | 0.6 | 2.5 |
| Loss on the sale of investments | 2.5 | | | | | 0.0 | | |
| Loss on disposal of property and equipment | 0.0 | | 0.1 | 0.1 | 0.1 | 0.0 | | 0.1 |
| Noncash interest expense | 0.0 | 0.0 | | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Changes in operating assets and liabilities: | | | | | | | | |
| Accounts receivable | 8.9 | -7.9 | 3.1 | 2.8 | -6.2 | 9.9 | -7.9 | 10.7 |
| Accounts receivable – related parties | 0.1 | | 0.1 | 0.1 | -0.1 | 0.1 | 1.4 | 1.3 |
| Inventory | -35.8 | -31.6 | 0.2 | 26.3 | 21.9 | 7.7 | 7.0 | -14.6 |
| Income tax receivable | 7.8 | 7.8 | 7.8 | 7.8 | 7.1 | 7.1 | 7.9 | 12.7 |
| Prepaid expenses | -0.2 | -0.2 | -0.1 | 0.0 | 0.2 | 0.3 | 0.4 | -0.3 |
| Prepaid expenses - related parties | | | | | | 0.0 | 0.0 | |
| Other assets | 2.5 | -4.4 | 0.8 | 0.5 | 0.2 | 0.8 | 0.7 | 0.7 |
| Accounts payable | -11.7 | 14.9 | 13.8 | -2.0 | -1.8 | -2.9 | 2.1 | 16.5 |
| Accounts payable - related parties | -0.4 | -0.1 | -0.1 | -0.4 | -0.7 | -0.8 | 6.9 | 7.7 |
| Accrued expenses and other current liabilities | 0.0 | -0.3 | -0.9 | 1.3 | 0.2 | 0.5 | 0.9 | -2.2 |
| Accrued expenses and other current liabilities – related parties | | 0.0 | 0.0 | | | 0.0 | | |
| Deferred revenue | -3.3 | -3.1 | -4.1 | -5.4 | -4.4 | -4.6 | -2.9 | -1.6 |
| Other noncurrent liabilities | 0.3 | -0.3 | -0.3 | -0.4 | -0.5 | -0.6 | -0.7 | -0.6 |
| Net cash used in operating activities | 20.0 | 33.2 | 52.5 | 68.4 | 44.5 | 47.9 | 44.1 | 39.7 |
| |
| Cash flows from investing activities | | | | | | | | |
| Collateralization of derivative instruments | -3.9 | 6.6 | -0.4 | 2.6 | 1.7 | -3.3 | -0.8 | -3.2 |
| Proceeds from the sale of marketable securities | 38.7 | | 1.3 | 0.3 | | 12.2 | | 42.7 |
| Proceeds from the sale of property and equipment | | | | 0.1 | | 0.1 | | |
| Capital expenditures | -6.8 | -6.3 | -4.8 | -4.5 | -2.9 | -2.3 | -1.5 | -1.4 |
| Net cash provided by (used in) investing activities | 28.0 | 1.4 | -3.8 | -3.4 | -2.5 | -1.2 | 15.0 | 16.5 |
| |
| Cash flows from financing activities | | | | | | | | |
| Payment of dividends | -10.5 | -10.5 | -10.5 | -10.5 | -10.5 | -119.9 | -119.9 | -119.9 |
| Deferred financing costs | | 0.0 | | | | | | |
| Net cash used in financing activities | -10.5 | -10.5 | -10.5 | -10.5 | -10.5 | -119.7 | -119.7 | -119.6 |
| Net change in cash and cash equivalents | 37.5 | 24.1 | 38.1 | 54.5 | 31.6 | -73.0 | -60.6 | -63.4 |
| Cash paid for income taxes | -0.2 | | 0.1 | 0.1 | 0.3 | | | 0.1 |
| |
| Noncash investing and financing activities: | | | | | | | | |
| Noncash capital expenditures | 0.4 | 0.3 | 0.2 | 0.5 | 0.4 | 0.4 | 0.4 | 0.0 |