Consolidated Statement of Earnings (Unaudited) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Income Statement [Abstract]
Commissions	$ 612.9	$ 594.6	$ 1,842.3	$ 1,748.6
Fees	375.0	360.7	1,087.8	1,051.2
Supplemental commissions	35.3	29.2	106.8	90.9
Contingent commissions	16.4	14.5	96.7	81.8
Investment income	13.6	13.1	36.4	38.5
Gains on books of business sales	1.1	2.6	4.7	7.0
Revenues from clean coal activities	429.3	408.1	1,036.0	1,009.0
Other net revenues (losses)	(1.3)	32.0	(0.9)	30.5
Total revenues	1,482.3	1,454.8	4,209.8	4,057.5
Compensation	626.6	604.9	1,879.7	1,795.2
Operating	189.6	208.1	598.7	618.7
Cost of revenues from clean coal activities	449.7	418.9	1,079.1	1,035.0
Interest	28.5	25.6	81.5	77.2
Depreciation	25.7	23.8	76.4	68.1
Amortization	63.2	58.1	185.1	172.3
Change in estimated acquisition earnout payables	4.1	9.7	21.2	25.9
Total expenses	1,387.4	1,349.1	3,921.7	3,792.4
Earnings before income taxes	94.9	105.7	288.1	265.1
Benefit for income taxes	(35.5)	(35.2)	(55.9)	(55.8)
Net earnings	130.4	140.9	344.0	320.9
Net earnings attributable to noncontrolling interests	7.6	7.6	24.7	26.4
Net earnings attributable to controlling interests	$ 122.8	$ 133.3	$ 319.3	$ 294.5
Basic net earnings per share	$ 0.69	$ 0.76	$ 1.80	$ 1.73
Diluted net earnings per share	0.69	0.75	1.79	1.71
Dividends declared per common share	$ 0.38	$ 0.37	$ 1.14	$ 1.11