| In millions, except per share items | Jun-30-17 | Mar-31-17 | Dec-31-16 | Sep-30-16 | Jun-30-16 | Mar-31-16 | Dec-31-15 | Sep-30-15 |
| | 10-Q | 10-Q | 10-K | 10-Q | 10-Q | 10-Q | 10-K | 10-Q |
| Net income | 18.9 | 12.3 | 36.2 | 21.6 | 17.8 | 15.7 | 27.5 | 13.2 |
| Depreciation and amortization | 7.6 | 7.1 | 7.7 | 7.9 | 7.7 | 7.5 | 7.4 | 7.3 |
| Stock-based compensation | 8.9 | 9.0 | 8.3 | 4.6 | 7.9 | 8.5 | 9.0 | 9.1 |
| Deferred taxes | 10.6 | 6.6 | -5.5 | -13.1 | 10.7 | 9.1 | -0.5 | -0.8 |
| Change in working capital [+] | 30.9 | 8.8 | -8.9 | -2.5 | 23.9 | -7.9 | -13.9 | 2.6 |
| Accounts receivable | 8.3 | 21.2 | -26.2 | 5.2 | 18.9 | -3.1 | -27.3 | 2.1 |
| Other current assets | -2.3 | -7.9 | 1.3 | 2.0 | -0.9 | 1.7 | 1.6 | 0.4 |
| Accrued expenses | 12.7 | -22.7 | 13.0 | 5.4 | 5.0 | -20.1 | 14.2 | 9.9 |
| Deferred revenues | 12.1 | 18.1 | 3.1 | -15.1 | 1.0 | 13.6 | -2.4 | -9.8 |
| Other operating activities | 0.5 | 1.1 | 1.1 | 1.1 | 0.9 | 0.9 | 0.9 | 3.1 |
| Cash from operations | 77.4 | 44.9 | 38.9 | 19.7 | 68.8 | 33.8 | 30.4 | 34.5 |
| |
| Capital expenditures [+] | -9.4 | -5.4 | -5.3 | -4.6 | -10.6 | -9.2 | -22.7 | -16.9 |
| Purchases of property and equipment | -9.4 | -5.4 | -5.3 | -4.6 | -10.6 | -9.2 | -22.7 | -16.9 |
| Sales of property and equipment | 0.9 | | | | | | | |
| Purchases of short-term investments, net | | | | 948.1 | | | | -0.1 |
| Purchases of short-term investments | | | | 948.1 | | | | |
| Sales of short-term investments | | | | | | | | -0.1 |
| Other cash from investing | 498.3 | -446.0 | 451.2 | -947.4 | -948.1 | 0.5 | | 0.1 |
| Cash from investing | 489.8 | -451.5 | 445.8 | -3.9 | -958.7 | -8.7 | -22.7 | -16.9 |
| |
| Repurchase of common stock, net | | | -1.2 | -22.4 | | | | -23.1 |
| Option exercises | 7.5 | 6.6 | 12.6 | 3.3 | 19.2 | 30.2 | 6.8 | 3.5 |
| Other cash from financing | 14.5 | 9.3 | -67.1 | 29.1 | 385.8 | -43.2 | 27.9 | -136.1 |
| Cash from financing | 7.0 | 2.7 | -80.9 | 3.3 | 366.6 | -73.4 | 21.2 | -162.7 |
| |
| Free cash flow | 68.0 | 39.4 | 33.5 | 15.1 | 58.2 | 24.6 | 7.7 | 17.6 |
| Per share (diluted) | $1.25 | $0.79 | $0.61 | $0.27 | $1.12 | $0.47 | $0.15 | $0.35 |