| 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 | 22.5 | 19.3 | 14.5 | -71.9 | 39.0 | -28.1 | 2.5 | 47.4 |
| Depreciation and amortization | 267.2 | 280.7 | 239.7 | 224.8 | 114.6 | 117.1 | 118.9 | 74.4 |
| Stock-based compensation | 18.2 | 18.8 | 14.7 | 23.0 | 9.2 | 14.4 | 6.6 | 7.2 |
| Tax benefit from stock-based compensation | -1.3 | -1.0 | -3.0 | | | | | |
| Deferred taxes | 18.0 | 9.2 | 6.7 | -31.4 | 17.2 | -18.5 | 3.3 | 33.6 |
| Change in working capital [+] | -77.3 | -25.5 | -74.1 | -52.8 | 72.3 | 69.5 | 26.9 | -20.2 |
| Accounts receivable | -4.8 | 42.8 | -14.7 | -10.4 | -16.3 | -5.4 | 4.3 | -2.6 |
| Other current assets | | | | | | | | -12.4 |
| Accounts payable | -2.5 | -3.7 | -23.1 | 0.1 | 0.9 | 5.5 | -1.8 | 1.5 |
| Accrued expenses | 8.7 | 13.1 | 4.2 | -37.5 | 14.6 | -4.2 | 14.3 | -5.0 |
| Deferred revenues | -61.8 | -61.8 | -32.8 | 14.1 | 73.6 | 73.6 | 9.9 | 2.5 |
| Other | -16.9 | -15.9 | -7.7 | -19.1 | -0.5 | | 0.2 | -4.2 |
| Other operating activities | 54.3 | 28.2 | 26.4 | 20.6 | 12.2 | -11.6 | -4.9 | 0.9 |
| Cash from operations | 301.6 | 329.7 | 224.9 | 112.3 | 264.5 | 142.8 | 153.3 | 143.3 |
| |
| Capital expenditures | -0.3 | -2.5 | -11.8 | -13.3 | -10.7 | -6.6 | -10.6 | -155.9 |
| Purchases of property and equipment | -0.3 | -2.5 | -11.8 | -13.3 | -10.7 | -6.6 | -10.6 | -155.9 |
| Acquisitions | -140.0 | | -35.7 | -524.0 | | | | |
| Other cash from investing | -198.0 | -167.4 | -217.1 | -257.2 | -205.3 | -252.9 | -70.3 | |
| Cash from investing | -338.3 | -169.9 | -264.6 | -794.5 | -216.0 | -259.5 | -80.9 | -191.1 |
| |
| Repurchase of common stock, net | -115.7 | -144.5 | -75.1 | | | | -0.3 | 21.2 |
| Option exercises | 3.2 | 5.6 | 11.1 | 39.6 | 4.2 | 1.8 | 10.2 | 1.9 |
| Financing costs | -37.6 | -3.0 | | -36.2 | | -11.1 | | -10.9 |
| Other cash from financing | 101.2 | -4.4 | 14.6 | 668.5 | 3.4 | 126.6 | 20.4 | 53.8 |
| Cash from financing | 19.9 | -151.5 | -71.6 | 665.1 | -0.8 | 135.9 | 9.9 | 84.0 |
| |
| Free cash flow | 301.3 | 327.2 | 213.1 | 99.0 | 253.8 | 136.2 | 142.7 | -12.6 |
| Per share (diluted) | $4.72 | $4.58 | $2.81 | $1.38 | $5.47 | $2.97 | $3.10 | ($0.28) |
| |
| Cash paid for interest | 14.0 | 24.0 | | | 5.4 | 23.2 | 30.2 | |
| Cash paid for income taxes | 0.1 | -0.5 | -11.0 | 13.9 | 1.5 | 1.7 | 4.2 | -2.4 |