| In millions, except per share items | Dec-31-19 | Dec-31-18 | Dec-31-16 | Dec-31-15 | Dec-31-12 | Dec-31-11 | Dec-31-10 | Dec-31-09 |
| | Source | Source | Source | Source | 10-K | 10-K | 10-K | 10-K |
| Net income | 0.0 | 0.0 | 0.0 | 0.0 | -9.5 | -2.1 | -11.2 | -11.4 |
| Depreciation and amortization | | | 21.2 | 37.4 | 98.9 | 71.5 | 98.8 | 109.7 |
| Asset impairment charges | 56.8 | | | | | | | |
| Stock-based compensation | | | 13.9 | 2.0 | 6.1 | 3.4 | 3.0 | 2.0 |
| Deferred taxes | | | | | 16.8 | 8.3 | 3.4 | -20.9 |
| Change in working capital [+] | | | -22.2 | 6.7 | 36.9 | 15.1 | 40.0 | -18.8 |
| Accounts receivable | | | | | | | | -2.7 |
| Inventories | | | | | | | | -5.6 |
| Other | | | -22.2 | 6.7 | 36.9 | 15.1 | 40.0 | -10.5 |
| Other operating activities | | | 40.4 | 14.1 | -55.0 | -72.5 | -37.3 | 36.4 |
| Cash from operations | 56.8 | 0.0 | 53.2 | 60.1 | 94.3 | 23.6 | 96.6 | 96.9 |
| |
| Capital expenditures | 0.0 | 0.0 | -0.6 | -1.4 | -45.1 | -51.4 | -30.8 | -12.5 |
| Purchases of property and equipment | | | -0.6 | -1.4 | -45.1 | -51.4 | -30.8 | -12.5 |
| Sales of short-term investments | | | | | 15.6 | | | |
| Sales of short-term investments | | | | | 15.6 | | | |
| Other cash from investing | | | -85.9 | -55.1 | -39.6 | -46.2 | -30.7 | -29.2 |
| Cash from investing | 0.0 | 0.0 | -86.5 | -56.5 | -69.1 | -97.6 | -61.6 | -41.7 |
| |
| Issuance of common stock, net | | | | | 0.3 | 0.3 | 2.2 | 73.5 |
| Other cash from financing | 57.4 | 35.0 | 19.9 | -7.9 | -50.3 | -0.7 | -13.4 | -8.2 |
| Cash from financing | 57.4 | 35.0 | 19.9 | -7.9 | -50.0 | -0.5 | -11.1 | 65.3 |
| |
| Free cash flow | 56.8 | 0.0 | 52.6 | 58.7 | 49.2 | -27.7 | 65.8 | 84.5 |
| Per share (diluted) | | | | | $0.19 | ($0.11) | $0.25 | $0.36 |