| In millions, except per share items | Jun-30-21 | Mar-31-21 | Dec-31-20 | Sep-30-20 | Jun-30-20 | Mar-31-20 | Dec-31-19 | Sep-30-19 |
| | 10-Q | 10-Q | 10-K/A | 10-Q | 10-Q | 10-Q | 10-K/A | 10-Q |
| Net income | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Depreciation and amortization | 0.1 | 0.1 | 0.1 | 0.1 | 0.1 | 0.1 | 0.1 | 0.1 |
| Stock-based compensation | 0.2 | 0.2 | 0.2 | 0.2 | 0.2 | 0.2 | 0.2 | 0.4 |
| Deferred taxes | -0.6 | | 0.9 | 0.5 | -0.9 | -0.8 | -0.5 | 0.9 |
| Change in working capital | 0.1 | -1.7 | 96.5 | 0.4 | -2.2 | -1.0 | -0.5 | 1.8 |
| Other | 0.1 | -1.7 | 96.5 | 0.4 | -2.2 | -1.0 | -0.5 | 1.8 |
| Other operating activities | -1.5 | 2.7 | -91.9 | 0.1 | 3.6 | 3.7 | 3.9 | 3.5 |
| Cash from operations | -1.6 | 1.3 | 5.8 | 1.3 | 0.8 | 2.3 | 3.2 | 6.7 |
| |
| Capital expenditures [+] | 0.0 | 0.0 | 0.0 | 0.0 | -0.1 | -0.1 | -0.2 | -0.2 |
| Purchases of property and equipment | | 0.0 | 0.0 | 0.0 | -0.1 | -0.1 | -0.2 | -0.2 |
| Sales of property and equipment | 0.1 | 0.0 | | | 0.1 | | | |
| Sales of short-term investments, net [+] | 38.7 | 3.1 | -11.2 | -1.5 | 1.7 | 1.4 | -3.6 | 3.5 |
| Purchases of short-term investments | | -10.1 | -19.7 | -3.0 | | | -5.0 | |
| Sales of short-term investments | 38.7 | 13.2 | 8.5 | 1.5 | 1.7 | 1.4 | 1.5 | 3.5 |
| Other cash from investing | 113.8 | -22.8 | 51.6 | 90.4 | -221.7 | -18.4 | 33.0 | -77.9 |
| Cash from investing | 152.7 | -19.7 | 40.4 | 88.9 | -220.0 | -17.2 | 29.2 | -74.6 |
| |
| Option exercises | 0.7 | 0.1 | | | | 0.1 | 0.5 | 0.0 |
| Other cash from financing | -47.3 | -9.4 | -38.2 | -71.0 | 86.2 | 186.8 | -22.6 | 13.5 |
| Cash from financing | -48.0 | -9.5 | -38.2 | -71.0 | 86.2 | 186.8 | -23.1 | 13.5 |
| |
| Free cash flow | -1.6 | 1.3 | 5.7 | 1.3 | 0.7 | 2.1 | 2.9 | 6.5 |
| Per share (diluted) | ($66.88) | $54.30 | $242.37 | $53.20 | $30.70 | $91.12 | $124.11 | $275.90 |
| |
| Cash paid for interest | 0.8 | 1.0 | 1.3 | 1.8 | 2.3 | 3.3 | 3.7 | 4.1 |