| In millions, except per share items | Dec-31-19 | Dec-31-18 | Dec-31-17 | Dec-31-16 | Dec-31-15 | Dec-31-14 | Dec-31-13 | Dec-31-12 |
| | 20-F | 20-F | 20-F | 20-F | 20-F | 20-F | 20-F | 20-F |
| Net income | -33.7 | -256.3 | 21.7 | -169.6 | -15.1 | 253.2 | 298.6 | 151.8 |
| Depreciation and amortization [+] | 25.2 | 25.9 | 27.6 | 25.0 | 14.7 | 11.6 | 9.7 | 6.4 |
| Depreciation | 25.2 | 25.9 | 27.6 | 25.0 | 14.7 | 11.6 | 9.7 | 6.4 |
| Asset impairment charges | | | 2.8 | 2.2 | | | | |
| Stock-based compensation | 8.8 | 14.1 | 7.2 | 6.6 | 4.5 | 4.7 | 7.0 | 7.1 |
| Deferred taxes | -10.5 | -21.3 | -0.3 | -2.3 | -32.4 | 27.3 | 15.5 | 24.9 |
| Change in working capital [+] | -14.5 | -41.2 | 39.9 | 254.9 | -11.5 | 53.7 | 56.5 | 27.3 |
| Accounts receivable | -19.0 | -18.4 | -0.4 | 16.2 | -118.8 | -22.7 | -25.5 | -14.6 |
| Other current assets | -5.5 | 3.4 | 9.4 | 16.7 | -35.3 | 8.8 | -12.3 | 1.3 |
| Accrued expenses | 2.7 | -42.9 | -39.3 | -17.6 | 106.4 | 50.1 | 41.4 | 27.0 |
| Deferred revenues | 12.6 | 12.6 | 30.3 | -6.5 | 33.1 | 4.4 | 46.4 | 4.5 |
| Income taxes | 1.3 | 1.3 | 8.8 | 30.9 | 57.4 | 15.1 | 6.4 | 7.5 |
| Other | -6.7 | 2.7 | 31.1 | 215.2 | -54.3 | -2.0 | 0.1 | 1.6 |
| Other operating activities | 93.9 | 333.8 | 28.1 | 14.4 | -125.5 | -136.1 | 20.7 | 1.4 |
| Cash from operations | 69.3 | 55.0 | 126.9 | 131.2 | -165.3 | 214.5 | 408.1 | 218.9 |
| |
| Capital expenditures [+] | -12.1 | -96.1 | -121.3 | -24.6 | -191.9 | -56.2 | -44.5 | -26.9 |
| Purchases of property and equipment | -12.1 | -96.1 | -65.9 | -24.6 | -45.2 | -8.0 | -6.7 | -18.1 |
| Capitalized product costs | | | -55.5 | | -146.7 | -48.2 | -37.7 | -8.8 |
| Sales of property and equipment | 0.0 | 0.2 | 5.8 | -127.7 | 0.6 | 0.1 | 0.1 | 0.3 |
| Acquisitions | | | | | | -9.8 | -12.8 | -111.4 |
| Sales of short-term investments, net [+] | -83.9 | -126.3 | -369.1 | -60.7 | 377.2 | 822.8 | 25.8 | 31.8 |
| Purchases of short-term investments | -249.9 | -721.7 | -383.1 | -73.8 | -129.8 | | | |
| Sales of short-term investments | 166.0 | 595.4 | 13.9 | 13.1 | 507.0 | 822.8 | 25.8 | 31.8 |
| Other cash from investing | 39.0 | 115.6 | 200.2 | 85.1 | -127.4 | -1,388.0 | -8.5 | -23.1 |
| Cash from investing | -57.0 | -106.7 | -284.5 | -127.9 | 58.6 | -631.1 | -39.8 | -129.3 |
| |
| Cash dividends paid | | | | | -82.8 | -82.4 | -81.0 | -131.0 |
| Repurchase of common stock, net | | | | -136.6 | | | | |
| Option exercises | 0.0 | 3.0 | 4.8 | 1.7 | 8.4 | 12.5 | 26.0 | 16.7 |
| Financing costs | -0.5 | | -0.3 | | 0.0 | -1.9 | -12.5 | -3.3 |
| Other cash from financing | -74.6 | 37.7 | 76.5 | -209.1 | 678.6 | 285.0 | 181.7 | 21.8 |
| Cash from financing | -74.1 | 34.7 | 72.0 | -347.3 | 587.5 | 192.1 | 87.1 | -122.6 |
| |
| Free cash flow | 57.2 | -41.1 | 61.0 | 106.7 | -210.5 | 206.5 | 401.3 | 200.8 |
| Per share (diluted) | $0.64 | ($0.46) | $0.06 | $1.14 | ($4.19) | $1.72 | $4.30 | $2.34 |
| |
| Cash paid for interest | 20.9 | 12.2 | 16.9 | 19.4 | 13.2 | 16.1 | 13.9 | 9.0 |