Consolidated Statement of Earnings - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Revenues before reimbursements	$ 8,076.4	$ 6,851.9	$ 7,056.4
Reimbursements	133.0	151.7	138.6
Total revenues	8,209.4	7,003.6	7,195.0
Compensation	3,927.5	3,466.5	3,339.5
Operating	1,072.4	906.5	1,068.5
Reimbursements	133.0	151.7	138.6
Cost of revenues from clean coal activities	1,173.2	882.1	1,352.8
Interest	226.1	196.4	179.8
Loss on extinguishment of debt	16.2
Depreciation	151.2	145.1	140.4
Amortization	415.1	417.3	334.0
Change in estimated acquisition earnout payables	119.6	(32.9)	15.3
Total expenses	7,234.3	6,132.7	6,568.9
Earnings before income taxes	975.1	870.9	626.1
Provision (benefit) for income taxes	20.1	12.8	(89.7)
Net earnings	955.0	858.1	715.8
Net earnings attributable to noncontrolling interests	48.2	39.3	47.0
Net earnings attributable to controlling interests	$ 906.8	$ 818.8	$ 668.8
Basic net earnings per share	$ 4.47	$ 4.29	$ 3.60
Diluted net earnings per share	4.37	4.20	3.52
Dividends declared per common share	$ 1.92	$ 1.80	$ 1.72
Commissions [Member]
Revenues before reimbursements	$ 4,132.3	$ 3,591.9	$ 3,320.6
Broker Fees [Member]
Revenues before reimbursements	2,264.1	1,957.9	1,911.1
Supplemental Revenue [Member]
Revenues before reimbursements	248.7	221.9	210.5
Contingent Revenue [Member]
Revenues before reimbursements	188.0	147.0	135.6
Investment income [Member]
Revenues before reimbursements	83.1	75.9	86.9
Net Gains (Losses) on Divestitures [Member]
Revenues before reimbursements	18.9	(5.8)	75.3
Clean Coal Activities [Member]
Revenues before reimbursements	1,140.8	863.5	1,319.3
Other Net Revenue (Losses) [Member]
Revenues before reimbursements	$ 0.5	$ (0.4)	$ (2.9)