| In millions, except per share items | Jun-30-23 | Mar-31-23 | Dec-31-22 | Sep-30-22 | Jun-30-22 | Mar-31-22 | Dec-31-21 | Sep-30-21 |
| | 10-Q | 10-Q | 8-K | 8-K | 10-Q | 10-Q | 10-K | 10-Q |
| Net income | 54.7 | 57.4 | 61.4 | 62.6 | 63.0 | 66.1 | 69.0 | 70.8 |
| Depreciation and amortization [+] | | | | | 3.7 | 3.7 | 3.7 | 3.8 |
| Depreciation | 1.3 | 1.4 | | | 3.0 | 3.0 | 3.1 | 3.1 |
| Amortization of intangible assets | 0.3 | 0.3 | 0.3 | 0.5 | 0.6 | 0.6 | 0.7 | 0.7 |
| Stock-based compensation | | | | | 2.4 | 2.3 | 2.4 | 2.4 |
| Deferred taxes | | | | | | | -0.6 | |
| Change in working capital | | | | | 2.8 | 2.7 | 0.0 | -0.9 |
| Other | | | | | 2.8 | 2.7 | 0.0 | -0.9 |
| Other operating activities | | | | | 56.6 | 49.3 | 68.2 | 61.5 |
| Cash from operations | | | | | 127.7 | 123.4 | 142.7 | 135.8 |
| |
| Capital expenditures | | | | | -2.1 | -1.8 | -1.9 | -4.0 |
| Purchases of property and equipment | | | | | -2.1 | -1.8 | -1.9 | -4.0 |
| Purchases of short-term investments, net | 51.3 | 89.5 | | | 81.8 | 461.1 | 527.1 | 1,139.4 |
| Purchases of short-term investments | | | | | -195.8 | 164.6 | 205.5 | 808.5 |
| Sales of short-term investments | 51.3 | 86.5 | | | 277.6 | 296.5 | 321.6 | 330.8 |
| Other cash from investing | | | | | -628.2 | -1,179.8 | -1,174.3 | -1,554.1 |
| Cash from investing | | | | | -548.5 | -720.4 | -649.1 | -418.7 |
| |
| Cash dividends paid | | | | | -19.6 | -20.1 | -21.1 | -19.0 |
| Repurchase of common stock, net | | | | | -17.5 | -10.6 | -10.1 | -5.5 |
| Other cash from financing | | | | | 430.6 | 398.9 | 612.4 | 340.6 |
| Cash from financing | | | | | 393.5 | 368.2 | 581.2 | 316.1 |
| |
| Free cash flow | | | | | 125.7 | 121.6 | 140.9 | 131.9 |
| Per share (diluted) | | | | | $8.45 | $8.14 | $9.40 | $8.79 |
| |
| Cash paid for interest | 41.2 | 21.2 | | | 11.2 | 10.5 | 11.2 | 12.3 |