| In millions, except per share items | Dec-31-16 | Dec-31-15 | Dec-31-14 | Dec-31-13 | Dec-31-12 | Dec-31-11 | Dec-31-10 | Dec-31-09 |
| | 10-K | 10-K | 10-K | 10-K | 10-K | 10-K | 10-K | 10-K |
| Net income | -66.0 | -7.5 | 17.0 | 92.9 | 29.7 | -49.6 | -37.6 | -27.7 |
| Depreciation and amortization | 3.6 | 3.3 | 2.0 | 1.3 | 2.4 | 4.0 | 7.5 | 11.0 |
| Stock-based compensation | 0.4 | 7.2 | 9.4 | 8.5 | 7.9 | 8.1 | 20.2 | 20.2 |
| Deferred taxes | 38.1 | -8.8 | 2.2 | -30.9 | | -0.2 | 0.1 | 0.4 |
| Change in working capital [+] | 51.9 | -22.4 | -34.0 | -8.6 | 16.9 | -37.9 | -77.4 | -319.6 |
| Accounts receivable | -1.7 | 2.2 | 0.8 | -2.0 | 0.1 | 5.6 | -4.8 | -3.6 |
| Other current assets | 1.0 | 1.5 | -0.5 | 1.0 | 3.4 | -2.4 | -1.4 | 7.2 |
| Other | 52.6 | -26.1 | -34.3 | -7.5 | 13.4 | -41.2 | -71.1 | -323.2 |
| Other operating activities | -51.5 | 8.5 | -15.6 | 36.1 | -18.9 | 10.2 | 53.6 | 325.0 |
| Cash from operations | -23.5 | -19.6 | -18.9 | 99.2 | 38.0 | -65.5 | -33.4 | 9.3 |
| |
| Capital expenditures | -0.8 | -2.3 | -9.5 | -0.9 | -0.5 | -1.3 | -2.8 | -1.3 |
| Purchases of property and equipment | -0.8 | -2.3 | -9.5 | -0.9 | -0.5 | -1.3 | -2.8 | -1.3 |
| Acquisitions | -1.3 | -2.2 | -1.0 | | | | -0.5 | -3.3 |
| Sales of short-term investments | 60.1 | 41.0 | 60.7 | 38.2 | 50.3 | 27.9 | 51.7 | 12.0 |
| Sales of short-term investments | 60.1 | 41.0 | 60.7 | 38.2 | 50.3 | 27.9 | 51.7 | 12.0 |
| Other cash from investing | -1.2 | -6.6 | -66.1 | -49.6 | -28.6 | -14.3 | -40.7 | 448.6 |
| Cash from investing | 56.9 | 29.9 | -16.0 | -12.3 | 21.2 | 12.3 | 7.7 | 456.0 |
| |
| Cash dividends paid | -6.2 | -2.9 | | | | | | |
| Repurchase of common stock, net | -22.4 | -48.3 | -65.9 | -59.4 | -20.9 | -22.5 | -13.8 | 18.5 |
| Other cash from financing | 0.2 | 2.1 | 1.8 | 5.4 | 0.8 | 0.1 | 0.0 | -416.0 |
| Cash from financing | -28.4 | -49.2 | -64.1 | -53.9 | -20.1 | -22.5 | -13.7 | -397.6 |
| |
| Free cash flow | -24.3 | -21.9 | -28.4 | 98.4 | 37.5 | -66.8 | -36.2 | 8.0 |
| Per share (diluted) | ($3.28) | ($2.71) | ($2.48) | $7.59 | $2.72 | ($4.39) | ($0.57) | $0.13 |
| |
| Cash paid for interest | 22.2 | 35.7 | 21.8 | | | | | 0.3 |
| Cash paid for income taxes | 0.2 | 0.0 | 3.3 | 3.4 | 0.3 | 0.1 | 5.1 | 0.0 |