| In millions, except per share items | Apr-30-23 | Oct-31-22 | Jul-31-22 | Apr-30-22 | Jan-31-22 | Oct-31-21 | Jul-31-21 | Apr-30-21 |
| | 10-Q | 10-Q | 10-Q | 10-Q | 10-K | 10-Q | 10-Q | 10-Q |
| CASH FLOWS FROM OPERATING ACTIVITIES | | | | | | | | |
| Net income | | 19.1 | 23.8 | 32.4 | 35.7 | 45.6 | 42.6 | 35.4 |
| |
| Adjustments to reconcile net income to net cash used in operating activities | | | | | | | | |
| Changes in accrued interest on investments | | | | -0.2 | | | | |
| Stock compensation expense | | 4.0 | 3.8 | 3.7 | 3.5 | 3.3 | 3.1 | 3.0 |
| Depreciation | | 3.1 | 3.2 | 3.3 | 3.4 | 3.5 | 3.6 | 3.7 |
| Lease expense | | 2.2 | 2.8 | 3.4 | 3.4 | 3.5 | 3.0 | 2.2 |
| Amortization of intangible assets | | 0.8 | 0.8 | 0.8 | 0.9 | 0.9 | 0.9 | 0.9 |
| Deferred income tax expense | | -0.8 | -0.8 | -0.4 | -0.2 | -0.3 | 0.1 | 0.0 |
| Other | | 0.1 | 0.3 | 0.1 | 0.0 | 0.0 | 0.1 | 0.2 |
| |
| Changes in operating assets and liabilities | | | | | | | | |
| Accounts receivable | | -4.3 | 16.0 | -5.9 | -0.5 | -5.2 | -13.5 | -10.2 |
| Contract assets | | -1.6 | 16.7 | 19.3 | 21.7 | 17.3 | 1.1 | 6.9 |
| Accounts payable and accrued expenses | | 6.3 | -13.1 | 0.6 | -5.7 | -16.2 | 17.9 | 18.5 |
| Net cash used in operating activities | | -86.3 | -75.5 | -28.7 | 28.4 | 75.2 | 120.3 | 153.2 |
| |
| CASH FLOWS FROM INVESTING ACTIVITIES | | | | | | | | |
| Purchases of short-term investments | | -249.8 | | -265.0 | | -90.0 | | |
| Maturities of short-term investments | | 280.0 | 220.0 | 180.0 | | 90.0 | 75.0 | |
| Purchases of property, plant and equipment | | -3.1 | -1.3 | -1.7 | -1.4 | -1.4 | -1.6 | |
| Net cash provided by (used in) investing activities | | -64.2 | -137.6 | -107.9 | -7.0 | -6.8 | -22.0 | 23.3 |
| |
| CASH FLOWS FROM FINANCING ACTIVITIES | | | | | | | | |
| Proceeds from the exercise of stock options | | | | 0.5 | 1.4 | 1.8 | | 2.5 |
| Net cash used in financing activities | | -97.9 | -88.0 | -62.4 | -34.6 | -29.7 | -29.5 | -44.6 |
| EFFECTS OF EXCHANGE RATE CHANGES ON CASH | | -7.1 | -6.9 | -5.4 | -3.0 | -0.3 | 0.2 | 1.9 |