| Fiscal period | 2024 | 2023 | 2022 | 2021 | 2020 | 2019 | 2018 | 2017 | 2016 | 2015 |
|---|
| Period End Date | 12/31/2024 | 12/31/2023 | 12/31/2022 | 12/31/2021 | 12/31/2020 | 12/31/2019 | 12/31/2018 | 12/31/2017 | 12/31/2016 | 12/31/2015 |
|---|
| Fee based services | -- | -- | -- | -- | -- | -- | -- | -- | -- | -- |
| Revenue | 23,432.90 | 20,760.80 | 20,862.10 | -- | -- | -- | -- | 7,932.40 | 6,803.80 | 5,965.67 |
| Revenue before reimbursements | -- | -- | -- | 11,045.60 | 8,900.10 | 10,030.60 | 9,089.50 | -- | -- | -- |
| Other Revenue | -- | -- | -- | -- | -- | -- | -- | -- | -- | -- |
| Equity in earnings from unconsolidated ventures | -- | -- | -- | -- | -- | -- | -- | -- | -- | -- |
| Reimbursements | -- | -- | -- | 8,321.40 | 7,689.80 | 7,952.60 | 7,228.90 | -- | -- | -- |
| Total Revenue | 23,432.90 | 20,760.80 | 20,862.10 | 19,367.00 | 16,589.90 | 17,983.20 | 16,318.40 | 7,932.40 | 6,803.80 | 5,965.67 |
| Compensation and benefits | 10,994.70 | 9,770.70 | 10,010.80 | 6,819.90 | 5,268.80 | 5,812.70 | 5,206.80 | 4,572.20 | 3,983.10 | 3,564.54 |
| Reimbursed expenses | -- | -- | -- | 8,321.40 | 7,689.80 | 7,952.60 | 7,228.90 | -- | -- | -- |
| Depreciation and amortization | 255.80 | 238.40 | 228.10 | 217.50 | 226.40 | 202.40 | 186.10 | 167.20 | 141.80 | 108.14 |
| Operating, administrative and other | 11,291.20 | 10,074.50 | 9,650.30 | 2,880.00 | 2,703.40 | 3,115.70 | 2,950.90 | 2,625.40 | 2,169.80 | 1,729.08 |
| Restructuring charges (credits), net | 23.10 | 100.70 | 104.80 | 84.70 | 142.40 | 184.40 | 38.80 | 30.70 | 68.50 | 34.12 |
| Restructuring charges: Compensation and benefits | -- | -- | -- | -- | -- | -- | -- | -- | -- | -- |
| Restructuring charges:Operating, administrative and other | -- | -- | -- | -- | -- | -- | -- | -- | -- | -- |
| Total operating expenses | 22,564.80 | 20,184.30 | 19,994.00 | 18,323.50 | 16,030.80 | 17,267.80 | 15,611.50 | 7,395.50 | 6,363.20 | 5,435.87 |
| Operating Income (Loss) | 868.10 | 576.50 | 868.10 | 1,043.50 | 559.10 | 715.40 | 706.90 | 536.90 | 440.60 | 529.80 |
| Interest expense, net of interest income | 136.90 | 135.40 | 75.20 | 40.10 | 52.80 | 56.40 | 51.10 | 56.20 | 45.30 | 28.13 |
| Gain on sale of investments | -- | -- | -- | -- | -- | -- | -- | -- | -- | -- |
| Equity in earnings from unconsolidated ventures | (70.80) | (194.10) | 51.00 | 209.40 | 8.00 | 36.30 | 32.80 | 44.40 | 33.80 | 77.48 |
| Other income | 18.90 | 4.90 | 150.30 | 10.80 | 15.30 | 2.30 | 17.40 | -- | 13.30 | -- |
| Gain (Loss) on extinguishment of Senior Notes | -- | -- | -- | -- | -- | -- | -- | -- | -- | -- |
| Income before provision for income taxes | 679.30 | 251.90 | 994.20 | 1,223.60 | 529.60 | 697.60 | 706.00 | 525.10 | 442.40 | 579.15 |
| Provision for Income Taxes - Total | 132.50 | 25.70 | 200.80 | 264.30 | 106.90 | 159.70 | 214.30 | 267.80 | 108.00 | 132.81 |
| State and local: Current | -- | -- | 29.20 | 34.60 | -- | 15.10 | 12.50 | 5.40 | 8.20 | -- |
| State and local: Deferred | -- | -- | 2.10 | 11.80 | -- | (7.00) | (5.00) | 19.10 | (4.00) | -- |
| U.S. Federal: Current | -- | -- | 81.70 | 95.10 | -- | 38.20 | 39.80 | 12.20 | 1.30 | -- |
| U.S. Federal: Deferred | -- | -- | (5.80) | 29.10 | -- | (12.90) | (20.10) | 122.20 | (11.10) | -- |
| International: Current | -- | -- | 136.30 | 156.00 | -- | 156.90 | 145.30 | 141.20 | 105.40 | -- |
| International: Deferred | -- | -- | (42.70) | (62.30) | -- | (31.30) | (1.40) | (15.70) | 8.20 | -- |
| Minority interest in income (losses) of subsidiaries | -- | -- | -- | -- | -- | -- | -- | -- | -- | -- |
| Net income before cumulative effect of change in accounting principle | -- | -- | -- | -- | -- | -- | -- | -- | -- | -- |
| Extraordinary gain on the acquisition of minority interest, net of tax | -- | -- | -- | -- | -- | -- | -- | -- | -- | -- |
| Cumulative effect of change in accounting principle, net of tax | -- | -- | -- | -- | -- | -- | -- | -- | -- | -- |
| Net (Loss)Income before Preferred Dividend & Noncontrolling Interest | 546.80 | 226.20 | 793.40 | 959.30 | 422.70 | 537.90 | 491.70 | 257.30 | 334.40 | 446.34 |
| Net income (loss) attributable to noncontrolling interest | -- | 0.80 | 138.90 | (2.30) | 20.20 | 2.60 | 7.20 | 3.10 | 16.20 | 7.67 |
| Dividends on unvested common stock, net of tax | -- | -- | -- | -- | -- | 0.90 | 0.40 | 0.40 | 0.40 | 0.31 |
| Net income (loss) available to common shareholders | 546.80 | 225.40 | 654.50 | 961.60 | 402.50 | 534.40 | 484.10 | 253.80 | 317.80 | 438.36 |
| EPS (BASIC): Basic earnings per common share before cumulative effect of change in accounting principle | -- | -- | -- | -- | -- | -- | -- | -- | -- | -- |
| EPS (BASIC): Extraordinary gain on the acquisition of minority interest, net of tax | -- | -- | -- | -- | -- | -- | -- | -- | -- | -- |
| EPS (BASIC): Dividends on unvested common stock, net | -- | -- | -- | -- | -- | -- | -- | -- | -- | -- |
| EPS (BASIC): Cumulative effect of change in accounting principle | -- | -- | -- | -- | -- | -- | -- | -- | -- | -- |
| Net Earnings Per Share (Basic) | 11.51 | 4.73 | 13.51 | 18.89 | 7.79 | 10.98 | 10.64 | 5.60 | 7.04 | 9.75 |
| EPS (DILUTED): Diluted earnings per common share before cumulative effect of change in accounting principle | -- | -- | -- | -- | -- | -- | -- | -- | -- | -- |
| EPS (BASIC): Extraordinary gain on the acquisition of minority interest, net of tax | -- | -- | -- | -- | -- | -- | -- | -- | -- | -- |
| EPS (DILUTED): Dividends on unvested common stock, net | -- | -- | -- | -- | -- | -- | -- | -- | -- | -- |
| EPS (DILUTED): Cumulative effect of change in accounting principle | -- | -- | -- | -- | -- | -- | -- | -- | -- | -- |
| Net Earnings Per Share (Diluted) | 11.30 | 4.67 | 13.27 | 18.47 | 7.70 | 10.87 | 10.54 | 5.55 | 6.98 | 9.65 |
| Weighted Average Shares Outstanding (Basic) | 47.49 | 47.63 | 48.45 | 50.92 | 51.68 | 48.65 | 45.52 | 45.32 | 45.15 | 44.94 |
| Weighted Average Shares Outstanding (Diluted) | 48.37 | 48.29 | 49.34 | 52.07 | 52.28 | 49.15 | 45.93 | 45.76 | 45.53 | 45.42 |