| In millions, except per share items | Dec-31-20 | Dec-31-19 | Dec-31-18 | Dec-31-17 | Dec-31-16 |
| | 10-K | 10-K | 10-K | 10-K | 10-K |
| Net income | -178.0 | -212.0 | -237.0 | 153.0 | 3.0 |
| Depreciation and amortization [+] | 171.0 | 203.0 | 160.0 | 148.0 | 147.0 |
| Depreciation | 159.0 | 181.0 | 160.0 | 148.0 | 147.0 |
| Amortization of intangible assets | 12.0 | 22.0 | | | |
| Asset impairment charges | 54.0 | 141.0 | 154.0 | 1.0 | 104.0 |
| Stock-based compensation | 10.0 | 11.0 | 11.0 | 16.0 | 14.0 |
| Deferred taxes | -6.0 | -1.0 | 6.0 | -112.0 | -12.0 |
| Change in working capital [+] | 3.0 | 8.0 | 10.0 | -38.0 | 7.0 |
| Accounts receivable | 8.0 | -9.0 | 9.0 | 2.0 | -9.0 |
| Other current assets | 7.0 | 9.0 | -11.0 | -31.0 | 3.0 |
| Other | -12.0 | 8.0 | 12.0 | -9.0 | 13.0 |
| Other operating activities | -92.0 | -34.0 | 7.0 | 14.0 | 1.0 |
| Cash from operations | -38.0 | 116.0 | 111.0 | 182.0 | 264.0 |
| |
| Capital expenditures [+] | -24.0 | -74.0 | -167.0 | -218.0 | -144.0 |
| Purchases of property and equipment | -24.0 | -74.0 | -167.0 | -218.0 | -144.0 |
| Sales of property and equipment | 274.0 | 173.0 | 7.0 | | 68.0 |
| Other cash from investing | -21.0 | 4.0 | 4.0 | 37.0 | 6.0 |
| Cash from investing | 229.0 | 103.0 | -156.0 | -181.0 | -70.0 |
| |
| Cash dividends paid | -22.0 | -46.0 | -16.0 | | |
| Repurchase of common stock, net | -1.0 | -31.0 | -6.0 | -3.0 | -102.0 |
| Financing costs | -1.0 | | -30.0 | | |
| Other cash from financing | -127.0 | -109.0 | -36.0 | -18.0 | -18.0 |
| Cash from financing | -149.0 | -186.0 | -28.0 | -21.0 | -120.0 |
| |
| Free cash flow | -62.0 | 42.0 | -56.0 | -36.0 | 120.0 |
| Per share (diluted) | ($1.10) | $0.74 | ($958,904.11) | ($0.62) | $2,030.46 |
| |
| Cash paid for interest | 36.0 | 52.0 | 81.0 | 77.0 | 77.0 |
| Cash paid for income taxes | 1.0 | 1.0 | 7.0 | 22.0 | 10.0 |