| In millions, except per share items | Mar-31-23 | Sep-30-22 | Jun-30-22 | Mar-31-22 | Dec-31-21 | Sep-30-21 | Jun-30-21 | Mar-31-21 |
| | 10-Q | 10-Q | 10-Q | 10-Q | 10-K | 10-Q | 10-Q | 10-Q |
| Net income | | 27.5 | 26.3 | 25.9 | 25.9 | 25.3 | 22.7 | 19.7 |
| Depreciation and amortization [+] | | 1.9 | 1.9 | 1.9 | 2.0 | 2.1 | 2.1 | 2.2 |
| Depreciation | | 1.5 | 1.5 | 1.5 | 1.5 | 1.6 | 1.6 | 1.6 |
| Amortization of intangible assets | | 0.4 | 0.4 | 0.5 | 0.5 | 0.5 | 0.5 | 0.6 |
| Stock-based compensation | | 0.8 | 0.8 | 0.8 | 0.8 | 0.7 | 0.6 | 0.5 |
| Deferred taxes | | 0.2 | 0.9 | 1.1 | 1.2 | 0.2 | -1.1 | -1.7 |
| Change in working capital | | -4.7 | -2.1 | -0.1 | 0.1 | 6.1 | 3.4 | -0.8 |
| Other | | -4.7 | -2.1 | -0.1 | 0.1 | 6.1 | 3.4 | -0.8 |
| Other operating activities | | 4.5 | 5.7 | 5.1 | 3.3 | 4.1 | 5.9 | 9.4 |
| Cash from operations | | 30.3 | 33.6 | 34.7 | 33.2 | 38.6 | 33.6 | 29.3 |
| |
| Capital expenditures [+] | | -1.7 | -1.6 | -2.2 | -2.6 | -2.3 | -2.3 | -0.9 |
| Purchases of property and equipment | | -1.7 | -1.6 | -2.2 | -2.6 | -2.3 | -2.3 | -0.9 |
| Sales of property and equipment | | | | | | | 0.0 | |
| Purchases of short-term investments, net | | -70.0 | -187.4 | -283.9 | -261.2 | -233.0 | -113.6 | -39.9 |
| Purchases of short-term investments | | -131.1 | -243.2 | -338.5 | -327.7 | -307.8 | -202.9 | -131.1 |
| Sales of short-term investments | | 61.0 | 55.9 | 54.6 | 66.5 | 74.8 | 89.3 | 91.1 |
| Other cash from investing | | -154.7 | -36.0 | -23.8 | 7.8 | 37.6 | -3.4 | -131.1 |
| Cash from investing | | -226.5 | -225.0 | -309.9 | -256.0 | -197.7 | -119.3 | -171.8 |
| |
| Cash dividends paid | | -3.6 | -3.5 | -3.4 | -3.2 | -3.1 | -3.0 | -2.8 |
| Repurchase of common stock, net | | -3.9 | -5.9 | -8.4 | -7.0 | -7.0 | -4.5 | -0.5 |
| Other cash from financing | | 109.8 | 150.1 | 212.3 | 295.6 | 128.7 | 85.6 | 307.9 |
| Cash from financing | | 102.3 | 140.7 | 200.5 | 285.4 | 118.7 | 78.1 | 304.6 |
| |
| Free cash flow | | 28.5 | 31.9 | 32.5 | 30.6 | 36.3 | 31.3 | 28.4 |
| Per share (diluted) | | $5.01 | $5.58 | $5.64 | $5.25 | $6.21 | $5.33 | $4.81 |
| |
| Cash paid for interest | | 5.3 | 4.1 | 3.9 | 4.4 | 3.2 | 4.6 | 5.8 |
| Cash paid for income taxes | | 8.1 | 7.2 | | 8.1 | 6.3 | 9.1 | |