| In millions, except per share items | Mar-31-21 | Dec-31-20 | Sep-30-20 | Jun-30-20 | Mar-31-20 | Dec-31-19 | Sep-30-19 | Jun-30-19 |
| | 10-Q | 10-K | 10-Q | 10-Q | 10-Q | 10-K | 10-Q | 10-Q |
| Revenues | 457.9 | 450.5 | 431.7 | 416.8 | 411.2 | 425.3 | 397.5 | 389.0 |
| Revenues growth | 11.4% | 5.9% | 8.6% | 7.2% | 2.0% | 2.4% | -0.4% | -2.0% |
| Operating expenses: | | | | | | | | |
| Direct salaries and related costs | 299.5 | 289.0 | 275.2 | 268.4 | 266.9 | 274.7 | 253.7 | 252.2 |
| General and administrative | 109.6 | 108.9 | 107.1 | 102.7 | 103.2 | 100.8 | 102.6 | 104.3 |
| Depreciation, net | 13.1 | 13.6 | 12.7 | 12.6 | 12.5 | 12.5 | 12.4 | 13.1 |
| Amortization of intangibles | 3.0 | 2.4 | 3.4 | 4.1 | 4.1 | 4.1 | 4.1 | 4.1 |
| Impairment of long-lived assets | 1.2 | 4.2 | 13.7 | | | | | |
| Total operating expenses | 426.4 | 418.3 | 433.8 | 389.6 | 386.8 | 392.2 | 372.8 | 373.8 |
| Income from operations | 31.5 | 32.3 | -2.1 | 27.2 | 24.4 | 33.1 | 24.7 | 15.3 |
| Operating margin | 6.9% | 7.2% | -0.5% | 6.5% | 5.9% | 7.8% | 6.2% | 3.9% |
| |
| Other income (expense): | | | | | | | | |
| Interest income | 0.1 | 0.2 | 0.1 | 0.2 | 0.3 | 0.2 | 0.2 | 0.2 |
| Interest (expense) | -0.4 | -0.3 | -0.4 | -0.6 | -0.7 | -0.9 | -1.1 | -1.2 |
| Other income (expense), net | -0.3 | 1.0 | 1.9 | 1.8 | -4.8 | -0.4 | -0.1 | -0.5 |
| Total other income (expense), net | -0.6 | 0.9 | 3.6 | 3.2 | -5.3 | -1.1 | -0.9 | -1.5 |
| Income before income taxes | 30.9 | 33.2 | -0.4 | 28.6 | 19.1 | 32.0 | 23.8 | 13.7 |
| Income taxes | 5.9 | 7.8 | 4.7 | 6.4 | 5.2 | 9.0 | 5.7 | 2.5 |
| Tax rate | 19.1% | 23.6% | | 22.3% | 27.3% | 28.1% | 23.9% | 18.0% |
| Net income | 25.0 | 25.4 | -5.1 | 22.2 | 13.9 | 23.0 | 18.1 | 11.3 |
| |
| Net income per common share: | | | | | | | | |
| Basic | $0.63 | $0.63 | ($0.13) | $0.55 | $0.34 | $0.56 | $0.44 | $0.27 |
| Diluted | $0.63 | $0.63 | ($0.13) | $0.55 | $0.34 | $0.55 | $0.44 | $0.27 |
| |
| Weighted average common shares outstanding: | | | | | | | | |
| Basic | 39.6 | 40.3 | 40.0 | 40.3 | 41.1 | 41.6 | 41.2 | 42.0 |
| Diluted | 40.0 | 40.5 | 40.0 | 40.4 | 41.3 | 41.8 | 41.3 | 42.1 |