| In millions, except per share items | Dec-31-22 | Dec-31-21 | Dec-31-20 | Dec-31-19 | Dec-31-18 | Dec-31-17 | Dec-31-16 | Dec-31-15 |
| | 10-K | 10-K | 10-K | 10-K | 10-K | 10-K | 10-K | 10-K |
| Net income | -92.6 | -282.8 | -383.5 | -279.7 | -143.6 | -73.7 | -135.7 | -60.7 |
| Depreciation and amortization [+] | 37.7 | 38.0 | 33.6 | 38.6 | 2.4 | 0.6 | 0.3 | 0.1 |
| Depreciation | 1.7 | 1.9 | 2.1 | 2.2 | 0.9 | 0.6 | 0.3 | 0.1 |
| Amortization of intangible assets | 36.0 | 36.0 | 31.5 | 36.4 | 1.5 | | | |
| Asset impairment charges | 30.2 | 15.6 | 135.6 | 7.1 | | | | |
| Stock-based compensation | 17.8 | 22.7 | 24.5 | 11.9 | 19.0 | 8.9 | 5.8 | 4.7 |
| Change in working capital [+] | -5.2 | -119.3 | 18.1 | -69.0 | 102.1 | 22.7 | -10.6 | 3.9 |
| Accounts receivable | 11.7 | -24.0 | 12.0 | -22.2 | 33.4 | -0.4 | -33.8 | |
| Inventories | 19.8 | -25.8 | 6.2 | -29.1 | 0.0 | | | |
| Other current assets | 0.4 | -18.7 | -8.1 | 10.5 | -1.0 | -4.2 | 0.4 | -1.0 |
| Accounts payable | 1.5 | -11.7 | 3.7 | 1.4 | 13.7 | 5.0 | -0.3 | 0.2 |
| Accrued expenses | -38.2 | -24.7 | 6.4 | -27.4 | 55.5 | 22.0 | 20.7 | 4.6 |
| Other | -0.3 | -14.3 | -2.0 | -2.2 | 0.4 | 0.3 | 2.4 | 0.0 |
| Other operating activities | -61.2 | 72.8 | 61.4 | 33.5 | -77.4 | -14.6 | 198.1 | -0.4 |
| Cash from operations | -73.2 | -253.0 | -110.4 | -257.4 | -97.5 | -56.2 | 57.9 | -52.4 |
| |
| Capital expenditures | -0.1 | -0.1 | -0.3 | -6.7 | -1.6 | -1.6 | -2.7 | -0.4 |
| Purchases of property and equipment | -0.1 | -0.1 | -0.3 | -6.7 | -1.6 | -1.6 | -2.7 | -0.4 |
| Sales of short-term investments, net [+] | | 40.0 | -39.7 | 217.8 | 32.1 | -175.6 | 15.4 | -13.3 |
| Purchases of short-term investments | | | -99.9 | | -224.2 | -330.6 | -147.0 | -77.2 |
| Sales of short-term investments | | 40.0 | 60.2 | 217.8 | 256.3 | 155.0 | 162.4 | 63.9 |
| Other cash from investing | | | | | 6.1 | | | |
| Cash from investing | -0.1 | 39.9 | -40.0 | 211.2 | 36.6 | -177.3 | 12.7 | -13.7 |
| |
| Issuance of common stock, net | 7.1 | 88.2 | 209.4 | 25.4 | 95.5 | 114.6 | 66.7 | 82.8 |
| Option exercises | 0.5 | 0.7 | 1.2 | 0.6 | 0.6 | 1.3 | 0.1 | 0.4 |
| Other cash from financing | 8.0 | 46.3 | 23.5 | 64.2 | 1.8 | 3.0 | 0.3 | 0.7 |
| Cash from financing | 14.6 | 133.7 | 231.7 | 89.0 | 96.6 | 116.2 | 66.9 | 83.1 |
| |
| Free cash flow | -73.3 | -253.0 | -110.7 | -264.1 | -99.1 | -57.8 | 55.2 | -52.8 |
| Per share (diluted) | ($0.40) | ($1.52) | ($0.80) | ($2.23) | ($1.71) | ($1.33) | $1.46 | ($2.00) |
| |
| Cash paid for interest | 6.8 | 9.6 | 7.8 | 0.8 | | | | |