| In millions, except per share items | Dec-31-21 | Dec-31-20 | Dec-31-19 | Dec-31-18 | Dec-31-17 | Dec-31-16 | Dec-31-15 | Dec-31-14 |
| | 10-K | 10-K | 10-K | 10-K | 10-K | 10-K | 10-K | S-1/A |
| Net income | -116.9 | -23.0 | -80.8 | -42.0 | -190.9 | -78.0 | -132.5 | 0.0 |
| Depreciation and amortization | 46.9 | 14.6 | 9.2 | 8.5 | 7.2 | 6.3 | 4.4 | 2.7 |
| Asset impairment charges | | 2.1 | | | | | | |
| Stock-based compensation | 54.7 | 37.0 | 27.8 | 20.4 | 11.1 | 8.4 | 5.6 | 5.2 |
| Change in working capital [+] | -313.2 | -8.0 | -56.2 | -17.5 | -0.5 | -4.3 | -1.9 | 3.5 |
| Accounts receivable | -7.1 | -35.5 | -3.9 | -2.0 | -2.7 | -5.0 | -2.7 | |
| Inventories | -309.1 | 25.4 | -51.9 | -19.3 | -3.4 | | | |
| Other current assets | | | | | | -8.8 | 0.7 | -0.1 |
| Accounts payable | 3.1 | 2.1 | -0.4 | 0.6 | -0.3 | 0.6 | 0.2 | 0.9 |
| Accrued expenses | | | | 4.4 | 5.1 | 6.6 | 3.9 | 3.4 |
| Other | | | | -1.2 | 0.7 | 2.2 | -4.0 | -0.7 |
| Other operating activities | 26.8 | 38.6 | -7.7 | -6.1 | 178.5 | 58.3 | 102.2 | -24.9 |
| Cash from operations | -301.6 | 61.3 | -107.6 | -36.7 | 5.4 | -9.4 | -22.2 | -13.6 |
| |
| Capital expenditures | -27.5 | -14.7 | -15.5 | -8.3 | -12.1 | -13.6 | -4.6 | -5.0 |
| Purchases of property and equipment | -27.5 | -14.7 | -15.5 | -8.3 | -12.1 | -13.6 | -4.6 | -5.0 |
| Acquisitions | -608.0 | | | | | | | -4.1 |
| Sales of short-term investments, net [+] | 106.8 | 147.9 | 24.4 | | 2.7 | | 0.0 | 0.0 |
| Purchases of short-term investments | | | | | | -1.7 | -1.6 | -1.5 |
| Sales of short-term investments | 106.8 | 147.9 | 24.4 | | 2.7 | 1.7 | 1.6 | 1.5 |
| Other cash from investing | -47.6 | -190.3 | -124.8 | -2.0 | -1.0 | | | |
| Cash from investing | -576.3 | -57.1 | -115.9 | -10.3 | -10.4 | -13.6 | -4.6 | -9.0 |
| |
| Cash dividends paid | | | | | | | -2.7 | |
| Issuance of common stock, net | | 69.7 | | 107.6 | 148.1 | | 2.7 | |
| Option exercises | 22.8 | 21.1 | 16.1 | 23.4 | 3.0 | 1.5 | 1.7 | 1.0 |
| Financing costs | -0.5 | 0.0 | -0.9 | | | | | |
| Other cash from financing | 672.6 | 645.6 | 47.1 | 189.2 | 4.7 | 3.2 | 5.3 | 70.6 |
| Cash from financing | 650.3 | 694.2 | 31.9 | 273.4 | 149.8 | 1.7 | 3.5 | 69.6 |
| |
| Free cash flow | -329.1 | 46.6 | -123.1 | -45.0 | -6.8 | -22.9 | -26.8 | -18.6 |
| Per share (diluted) | ($3.14) | $0.47 | ($1.34) | ($0.53) | ($0.16) | ($1.59) | ($2.00) | |
| |
| Cash paid for interest | 7.6 | 5.0 | 2.5 | | | | | |