| In millions, except per share items | Jun-30-23 | Mar-31-23 | Dec-31-22 | Jun-30-22 | Mar-31-22 | Dec-31-21 | Sep-30-21 | Jun-30-21 |
| | 10-Q | 10-Q | 8-K | 10-Q | 10-Q | 10-K | 8-K | 10-Q |
| Cost of services | 4,324.5 | 3,855.6 | 3,749.1 | 3,607.4 | 3,417.4 | | | 2,552.1 |
| Gross profit | 724.1 | 573.2 | 667.6 | 624.6 | 548.2 | 598.0 | 534.7 | 447.7 |
| Equity in earnings of integral unconsolidated affiliates | 9.4 | 9.6 | 8.1 | 18.6 | 15.2 | 21.2 | 10.2 | 7.5 |
| Selling, general and administrative expenses | 384.2 | 384.6 | 341.1 | 323.2 | 324.9 | 367.6 | 274.8 | 270.1 |
| Amortization of intangible assets | 70.0 | 72.4 | 63.1 | 107.9 | 115.8 | 99.9 | 22.8 | 21.3 |
| Asset impairment charges | | | 11.7 | 2.8 | | 3.4 | | 2.3 |
| Change in fair value of contingent consideration liabilities | | | | -0.8 | -5.2 | -6.7 | | 0.2 |
| Operating income | 279.3 | 125.9 | 259.4 | 208.4 | 117.5 | 140.1 | 248.1 | 161.7 |
| Interest and other financing expenses | -48.2 | -41.7 | | -28.6 | -24.7 | | | -13.1 |
| Interest income | 1.4 | 1.5 | 1.9 | 0.2 | 0.1 | | | 2.9 |
| Other income (expense), net | 3.4 | 7.9 | | -42.5 | -1.3 | | | 8.5 |
| Income before income taxes | 236.0 | 93.5 | | 137.4 | 91.6 | | | 159.9 |
| Provision for income taxes | 69.4 | -3.4 | 71.5 | 41.3 | 6.6 | 14.7 | 61.6 | 41.0 |
| Net income | 166.6 | 97.0 | | 96.2 | 85.0 | | | 119.0 |
| Less: Net income attributable to non-controlling interests | 0.7 | 1.9 | 11.6 | 8.1 | 0.4 | 1.5 | 1.0 | 1.9 |
| Net income attributable to common stock | 165.9 | 95.0 | | 88.0 | 84.6 | | | 117.0 |
| |
| Earnings per share attributable to common stock: | | | | | | | | |
| Basic (in dollars per share) | $1.14 | $0.66 | | $0.61 | $0.59 | | | $0.83 |
| Diluted (in dollars per share) | $1.12 | $0.64 | | $0.59 | $0.57 | | | $0.81 |
| |
| Shares used in computing earnings per share: | | | | | | | | |
| Weighted average basic shares outstanding (in shares) | 145.4 | 144.5 | 143.2 | 143.9 | 143.5 | 140.8 | 140.0 | 140.3 |
| Weighted average diluted shares outstanding (in shares) | 148.8 | 148.7 | 147.5 | 148.2 | 148.1 | 145.4 | 144.3 | 144.6 |