| In millions, except per share items | Jun-30-23 | Dec-31-22 | Jun-30-22 | Mar-31-22 | Dec-31-21 | Sep-30-21 | Jun-30-21 | Mar-31-21 |
| | 10-Q | 10-K | 10-Q | 10-Q | 10-K | 10-Q | 10-Q | 10-Q |
| ASSETS | | | | | | | | |
| Current assets | | | | | | | | |
| Cash and cash equivalents | 83.1 | 96.5 | 77.6 | 83.6 | 63.4 | 58.6 | 66.5 | 70.8 |
| Restricted cash | 1.0 | | | | | | | |
| Short-term investments | | 2.3 | 20.2 | 36.3 | 35.1 | 39.2 | 42.7 | 44.4 |
| Accounts receivable, net of allowances of $1,552 in 2023 and $1,600 in 2022 | 38.2 | 65.1 | 39.9 | 35.7 | 56.6 | 44.8 | 45.8 | 47.9 |
| Inventories, net | 15.0 | 12.1 | 10.0 | 10.4 | 10.3 | 11.7 | 9.5 | 11.3 |
| Prepaid expenses | 7.9 | 6.2 | 7.1 | 7.7 | 7.6 | 8.4 | 7.8 | 7.6 |
| Contract assets | 5.5 | 4.5 | 5.1 | 5.4 | 4.7 | 4.6 | 5.2 | 5.1 |
| Other current assets | 9.3 | 10.8 | 10.6 | 9.6 | 9.4 | 11.0 | 9.9 | 9.6 |
| Total current assets | 160.0 | 197.5 | 170.5 | 188.7 | 187.1 | 178.3 | 187.4 | 196.7 |
| Property and equipment, net | 15.6 | 12.7 | 10.1 | 10.3 | 10.8 | 11.0 | 11.5 | 11.7 |
| Operating lease right-of-use assets | 4.7 | 8.0 | 8.1 | 8.8 | 9.2 | 9.7 | 10.0 | 10.6 |
| Goodwill | 93.3 | 90.5 | 90.4 | 94.6 | 96.2 | 96.2 | 97.8 | 97.5 |
| Intangible assets, net of accumulated amortization | 12.6 | 12.5 | 18.1 | 19.7 | 21.3 | 22.6 | 24.2 | 25.7 |
| Deferred income taxes | 1.9 | 1.9 | 3.5 | 3.7 | 3.8 | 10.3 | 8.9 | 7.5 |
| Other assets | 10.6 | 11.9 | 10.5 | 9.8 | 14.0 | 13.0 | 12.7 | 11.5 |
| Total assets | 298.6 | 335.1 | 311.9 | 335.9 | 342.3 | 341.3 | 354.3 | 362.5 |
| |
| LIABILITIES AND STOCKHOLDERS' EQUITY | | | | | | | | |
| Current liabilities | | | | | | | | |
| Accounts payable | 17.6 | 17.4 | 9.1 | 7.2 | 8.2 | 7.9 | 6.9 | 5.8 |
| Deferred revenue | 52.4 | 64.6 | 48.3 | 51.0 | 54.6 | 42.4 | 43.1 | 43.2 |
| Accrued wages and payroll taxes | 16.5 | 18.7 | 13.5 | 14.2 | 17.5 | 14.9 | 15.7 | 15.3 |
| Short-term income taxes payable | 2.4 | 2.4 | 1.4 | 0.7 | 1.1 | 1.0 | 1.0 | 1.0 |
| Other accrued expenses | 8.5 | 7.7 | 6.6 | 7.3 | 7.7 | 7.2 | 10.2 | 9.4 |
| Deferred compensation | 16.5 | 18.7 | 13.5 | 14.2 | 17.5 | 14.9 | 15.7 | 15.3 |
| Total current liabilities | 97.3 | 110.8 | 79.0 | 80.4 | 89.1 | 73.3 | 76.9 | 74.6 |
| Long-term deferred revenue | 4.9 | 6.3 | 7.0 | 7.3 | 9.1 | 10.0 | 10.7 | 11.7 |
| Long-term lease liabilities | 5.5 | 8.4 | 9.2 | 9.9 | 10.2 | 10.6 | 11.2 | 11.7 |
| Long-term income taxes payable | | 2.6 | 3.1 | 5.1 | 5.1 | 5.0 | 5.0 | 6.1 |
| Deferred income taxes | 1.2 | 1.2 | 1.9 | 2.0 | 1.3 | 1.6 | 1.7 | 1.7 |
| Other long-term liabilities | 3.0 | 2.5 | 7.3 | 7.6 | 7.8 | 10.1 | 10.2 | 10.2 |
| Total liabilities | 112.0 | 131.8 | 107.6 | 112.3 | 122.5 | 110.7 | 115.7 | 116.0 |
| |
| Stockholders' equity | | | | | | | | |
| Common stock: $0.001 par value per share | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Additional paid-in capital | 114.1 | 107.3 | 102.1 | 101.0 | 100.3 | 99.0 | 99.2 | 98.0 |
| Treasury stock, at cost, 1,038 shares outstanding at June 30, 2023 and December 31, 2022 | -18.2 | | | | | | | |
| Retained earnings | 102.6 | 128.7 | 139.0 | 148.4 | 143.2 | 156.9 | 157.9 | 164.6 |
| Accumulated other comprehensive loss | -11.9 | -14.6 | -18.7 | -13.3 | -11.2 | -12.9 | -10.6 | -11.2 |
| Total stockholders' equity | 186.6 | 203.3 | 204.3 | 223.6 | 219.8 | 230.6 | 238.6 | 246.5 |
| Total liabilities and stockholders' equity | 298.6 | 335.1 | 311.9 | 335.9 | 342.3 | 341.3 | 354.3 | 362.5 |