| In millions, except per share items | Dec-31-22 | Dec-31-21 | Dec-31-20 | Dec-31-19 | Dec-31-18 | Dec-31-17 | Dec-31-16 | Dec-31-15 |
| | 10-K | 10-K | 10-K | 10-K | 10-K | 10-K | 10-K | 10-K |
| Net income | 70.5 | 193.3 | 223.6 | 152.0 | 183.0 | 136.9 | 161.0 | 132.6 |
| Depreciation and amortization | 166.6 | 150.7 | 139.5 | 117.7 | 96.7 | 91.2 | 70.7 | 64.4 |
| Stock-based compensation | 83.2 | 41.9 | 36.6 | 44.4 | 31.7 | 24.1 | 14.5 | 17.4 |
| Deferred taxes | -37.3 | -12.1 | -6.7 | -6.0 | -1.1 | -14.1 | 4.7 | 2.9 |
| Change in working capital [+] | 8.5 | 69.4 | 39.7 | 48.1 | 8.2 | 32.0 | 4.0 | 25.7 |
| Accounts receivable | -38.6 | -67.9 | -9.2 | 11.3 | -29.6 | -1.2 | -0.1 | -6.9 |
| Deferred revenues | 60.0 | 78.2 | 29.5 | 28.1 | 28.6 | 2.5 | 6.7 | 10.6 |
| Income taxes | 26.6 | -6.0 | 10.7 | -13.7 | -12.6 | 9.8 | 0.9 | 8.1 |
| Other | -39.5 | 65.1 | 8.7 | 22.4 | 21.8 | 20.9 | -3.5 | 13.9 |
| Other operating activities | 6.3 | 6.7 | -48.4 | -21.8 | -3.7 | -20.0 | -41.2 | -1.5 |
| Cash from operations | 297.8 | 449.9 | 384.3 | 334.4 | 314.8 | 250.1 | 213.7 | 241.5 |
| |
| Capital expenditures | -129.5 | -101.8 | -76.7 | -80.0 | -76.1 | -66.6 | -62.8 | -57.3 |
| Purchases of property and equipment | -129.5 | -101.8 | -76.7 | -80.0 | -76.1 | -66.6 | -62.8 | -57.3 |
| Acquisitions | -646.7 | -24.8 | -67.8 | -681.9 | -0.4 | -1.0 | -191.6 | -11.1 |
| Purchases of short-term investments, net | -36.5 | -71.1 | -56.4 | -36.2 | -35.7 | | | 30.0 |
| Purchases of short-term investments | -36.5 | -71.1 | -56.4 | -36.2 | -35.7 | | | |
| Sales of short-term investments | | | | | | | | 30.0 |
| Other cash from investing | 13.4 | 30.0 | 77.1 | 51.8 | 62.3 | 6.8 | -19.8 | -41.1 |
| Cash from investing | -799.3 | -167.7 | -123.8 | -746.3 | -49.9 | -60.8 | -274.2 | -79.5 |
| |
| Cash dividends paid | -61.5 | -54.2 | -51.4 | -47.8 | -42.6 | -39.3 | -37.9 | -33.7 |
| Repurchase of common stock, net | -226.0 | -1.3 | 308.1 | -4.9 | -20.9 | -42.3 | -48.8 | -97.0 |
| Option exercises | | 0.2 | 1.9 | 0.2 | 0.1 | 0.2 | 0.4 | 3.9 |
| Other cash from financing | 702.6 | -156.1 | -437.0 | 426.6 | -125.2 | -75.7 | 210.8 | 7.1 |
| Cash from financing | 415.1 | -211.8 | -182.2 | 373.7 | -188.8 | -157.5 | 123.7 | -127.5 |
| |
| Free cash flow | 168.3 | 348.1 | 307.6 | 254.4 | 238.7 | 183.5 | 150.9 | 184.2 |
| Per share (diluted) | $3.92 | $8.02 | $7.12 | $5.89 | $5.55 | $4.27 | $3.48 | $4.16 |
| |
| Cash paid for interest | 28.4 | 10.4 | 11.1 | 11.0 | 3.7 | 5.4 | 1.2 | 0.4 |
| Cash paid for income taxes | 75.3 | 80.9 | 58.2 | 63.3 | 67.0 | 47.1 | 58.0 | 50.1 |