| In millions, except per share items | Dec-31-22 | Dec-31-21 | Dec-31-20 | Dec-31-19 | Dec-31-18 | Dec-31-17 |
| | 10-K | 10-K | 10-K | 10-K | 10-K | 10-K/A |
| Net income | -168.7 | -396.1 | -73.1 | 2,332.4 | -21.6 | -1.5 |
| Depreciation and amortization | 13.1 | 15.4 | 7.0 | 4.3 | 1.9 | 0.8 |
| Asset impairment charges | 64.9 | 375.6 | 66.1 | 29.2 | | |
| Stock-based compensation | 15.1 | 10.2 | 15.4 | 11.6 | 8.2 | 1.9 |
| Change in working capital [+] | 14.6 | 136.6 | 45.0 | 10.1 | 16.1 | 4.7 |
| Accounts receivable | -2.7 | -13.2 | -4.7 | -0.6 | | |
| Inventories | -7.2 | 11.6 | -0.7 | -23.1 | | |
| Other current assets | 1.0 | 3.1 | | -4.6 | | |
| Accounts payable | -0.9 | -1.6 | -2.8 | 0.0 | 12.7 | 5.2 |
| Other | 24.4 | 136.7 | 53.3 | 38.4 | 3.4 | -0.4 |
| Other operating activities | -28.0 | -295.3 | -205.2 | -2,518.8 | -12.1 | -10.2 |
| Cash from operations | -88.9 | -153.6 | -144.9 | -131.2 | -7.5 | -4.3 |
| |
| Capital expenditures | -3.5 | -11.1 | -31.4 | -38.7 | -88.3 | -32.9 |
| Purchases of property and equipment | -3.5 | -11.1 | -31.4 | -38.7 | -88.3 | -32.9 |
| Purchases of intangible assets | -1.6 | -1.1 | -4.0 | -0.3 | -0.3 | |
| Acquisitions | | | | -224.3 | | |
| Purchases of short-term investments, net | -2.5 | 95.7 | 95.4 | -280.3 | | |
| Purchases of short-term investments | -271.4 | -119.6 | -201.3 | -299.9 | | |
| Sales of short-term investments | 268.9 | 215.3 | 296.7 | 19.6 | | |
| Other cash from investing | 5.7 | -112.3 | -39.9 | -59.7 | -5.3 | 3.0 |
| Cash from investing | -1.8 | -28.9 | 20.2 | -603.3 | -93.9 | -29.9 |
| |
| Financing costs | | | | | | -1.0 |
| Other cash from financing | -2.9 | -13.4 | -3.1 | 1,857.9 | 122.1 | 38.1 |
| Cash from financing | -2.9 | -13.4 | -3.1 | 1,857.9 | 122.1 | 39.1 |
| |
| Free cash flow | -92.4 | -164.8 | -176.3 | -169.9 | -95.8 | -37.2 |
| Per share (diluted) | ($0.25) | ($0.44) | ($0.50) | ($0.50) | ($0.56) | ($0.21) |
| |
| Cash paid for interest | | | | 0.8 | | |
| Cash paid for income taxes | 0.2 | 0.9 | | | | |