| In millions, except per share items | Mar-31-19 | Dec-31-18 | Sep-30-18 | Jun-30-18 | Mar-31-18 | Dec-31-17 | Sep-30-17 | Jun-30-17 |
| | 10-Q | 10-K | 10-Q | 10-Q | 10-Q | 10-K | 10-Q | 10-Q |
| Net income | 40.9 | 43.8 | 19.4 | 18.7 | 15.8 | 15.7 | 13.6 | 10.4 |
| Depreciation and amortization [+] | 9.7 | 9.4 | 9.4 | 9.3 | 9.2 | 8.9 | 8.7 | 8.5 |
| Depreciation | 4.1 | 3.9 | 3.8 | 3.8 | 3.7 | 3.7 | 3.6 | 3.5 |
| Amortization of intangible assets | 5.6 | 5.5 | 5.6 | 5.5 | 5.4 | 5.2 | 5.1 | 5.0 |
| Stock-based compensation | 13.7 | 13.5 | 13.0 | 12.6 | 12.2 | 12.1 | 11.6 | 10.6 |
| Change in working capital [+] | -13.5 | -9.5 | -11.2 | -13.0 | -14.6 | -9.1 | -4.2 | -0.7 |
| Accounts receivable | -5.7 | -4.5 | -5.6 | -4.3 | -4.1 | -5.1 | -5.2 | -3.4 |
| Inventories | -6.1 | -6.3 | -9.0 | -10.9 | -10.4 | -9.3 | -0.2 | 2.0 |
| Other current assets | -3.8 | -1.7 | -1.6 | -2.9 | -1.9 | -0.6 | -0.2 | 0.9 |
| Accounts payable | 2.0 | 1.9 | 4.7 | 6.0 | 2.6 | 6.4 | 1.1 | -0.9 |
| Accrued expenses | -0.4 | -0.1 | 0.0 | -0.9 | -0.9 | -0.4 | -0.1 | -0.2 |
| Deferred revenues | | | 0.0 | 0.0 | | 0.2 | 0.2 | 0.7 |
| Other | 0.6 | 1.4 | 0.3 | -0.1 | -0.1 | -0.2 | 0.1 | 0.2 |
| Other operating activities | -21.0 | -22.3 | 3.4 | 3.1 | 2.9 | -0.1 | -2.0 | -2.1 |
| Cash from operations | 29.8 | 35.0 | 34.0 | 30.7 | 25.4 | 27.4 | 27.7 | 26.6 |
| |
| Capital expenditures | -6.6 | -6.3 | -4.9 | -4.2 | -3.9 | -4.0 | -3.9 | -3.1 |
| Purchases of property and equipment | -6.6 | -6.3 | -4.9 | -4.2 | -3.9 | -4.0 | -3.9 | -3.1 |
| Acquisitions | -13.1 | | -2.8 | -1.7 | | -9.3 | | -7.9 |
| Purchases of short-term investments, net | 5.2 | 3.8 | -12.3 | -21.0 | -29.2 | -29.1 | -16.7 | -9.1 |
| Purchases of short-term investments | -70.3 | -62.6 | -75.9 | -80.2 | -81.6 | -76.8 | -61.6 | -46.2 |
| Sales of short-term investments | 75.4 | 66.5 | 63.6 | 59.3 | 52.4 | 47.7 | 44.9 | 37.1 |
| Cash from investing | -14.5 | -3.9 | -20.0 | -26.9 | -34.5 | -42.3 | -28.5 | -20.1 |
| |
| Repurchase of common stock, net | -18.9 | -23.9 | -16.0 | -11.1 | -7.4 | | | |
| Option exercises | 9.2 | 11.0 | 16.4 | 12.3 | 15.5 | 17.0 | 11.7 | 10.5 |
| Financing costs | | | | | -0.1 | | | |
| Other cash from financing | 12.8 | 14.4 | 25.2 | 16.9 | 23.7 | 28.4 | 17.0 | 12.9 |
| Cash from financing | -15.3 | -20.4 | -7.0 | -6.4 | 0.9 | 9.6 | 3.5 | 0.6 |
| |
| Free cash flow | 23.2 | 28.7 | 29.2 | 26.5 | 21.5 | 23.5 | 23.8 | 23.4 |
| Per share (diluted) | $0.85 | $1.04 | $1.07 | $0.98 | $0.80 | $0.89 | $0.92 | $0.93 |
| |
| Cash paid for interest | 0.2 | 0.1 | 0.1 | 0.1 | 0.0 | 0.1 | 0.1 | 0.2 |
| Cash paid for income taxes | 1.2 | 1.2 | 1.0 | 1.0 | 1.3 | | 1.4 | 1.3 |