| 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 |
| Net income | 5.3 | 6.8 | 8.3 | 8.0 | 8.0 | 9.3 | 6.8 | 8.1 |
| Depreciation and amortization [+] | 0.8 | 0.7 | 0.7 | 0.7 | 0.7 | 1.5 | 1.2 | 2.1 |
| Depreciation | 1.2 | 1.1 | 1.1 | 1.1 | 1.1 | 1.4 | 1.2 | 1.2 |
| Amortization of intangible assets | 0.0 | 0.0 | 0.0 | 0.0 | 0.1 | 0.1 | 0.1 | 0.1 |
| Stock-based compensation | 0.3 | 0.2 | 0.2 | 0.2 | 0.1 | 0.1 | 0.1 | -2.8 |
| Deferred taxes | 0.2 | 0.1 | -0.1 | 9.8 | 0.4 | 0.3 | 0.5 | -0.5 |
| Change in working capital [+] | -4.2 | -2.5 | 1.9 | 33.1 | -1.1 | 41.3 | 41.9 | 27.2 |
| Accrued expenses | 1.3 | 0.6 | 2.8 | 34.7 | -0.5 | 41.9 | 42.3 | 14.6 |
| Other | -5.5 | -3.1 | -0.8 | -2.0 | -1.0 | -0.6 | -0.4 | 13.1 |
| Other operating activities | 23.2 | 24.2 | 28.8 | -21.1 | 19.8 | -21.0 | -29.2 | 43.3 |
| Cash from operations | 25.5 | 29.7 | 39.9 | 30.7 | 27.9 | 31.5 | 21.3 | 77.6 |
| |
| Capital expenditures [+] | -6.5 | -2.4 | -3.6 | -2.8 | -2.7 | -2.5 | -0.6 | -1.2 |
| Purchases of property and equipment | -6.5 | -2.4 | -3.6 | -2.8 | -2.7 | -2.5 | -0.6 | -1.2 |
| Sales of property and equipment | 0.1 | | | | 0.1 | | 0.1 | 0.2 |
| Sales of short-term investments, net [+] | | | 40.8 | 8.5 | 8.7 | | | |
| Purchases of short-term investments | | | 0.0 | -0.2 | | | | |
| Sales of short-term investments | | | 40.8 | | 8.7 | | | |
| Other cash from investing | -77.6 | -114.9 | -185.1 | -270.6 | -340.0 | -322.5 | -243.2 | -78.6 |
| Cash from investing | -51.8 | -76.4 | -147.9 | -278.9 | -347.8 | -324.9 | -243.7 | -66.5 |
| |
| Cash dividends paid | -3.6 | -3.6 | -3.6 | -3.6 | -3.6 | -4.5 | -3.6 | -3.6 |
| Issuance of common stock, net | 0.5 | | 0.5 | | 0.5 | | 0.3 | |
| Other cash from financing | 48.7 | 32.7 | 57.9 | 101.1 | 154.3 | 267.6 | 235.5 | 138.6 |
| Cash from financing | 45.6 | 29.6 | 54.8 | 98.0 | 151.2 | 263.3 | 232.1 | 134.8 |
| |
| Free cash flow | 19.0 | 27.3 | 36.3 | 27.9 | 25.2 | 29.1 | 20.7 | 76.3 |
| Per share (diluted) | $5.49 | $7.89 | $10.52 | $8.09 | $7.34 | $8.48 | $8.07 | $29.75 |
| |
| Cash paid for interest | 15.8 | 11.0 | 7.4 | 4.5 | 4.0 | 5.3 | 4.1 | 4.8 |
| Cash paid for income taxes | | 0.4 | | | | | | 2.2 |