STATEMENT OF CHANGES IN EQUITY AND ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) - Statement of Changes in Equity (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2019
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	$ 1,536.0	$ 1,242.4	$ 1,425.1	$ 1,341.9
Net earnings	97.2	107.1	297.0	145.1
Dividends declared	(56.1)	(53.0)	(165.4)	(158.8)
Treasury stock purchased	(0.3)	(1.9)	(12.1)	(10.5)
Treasury stock issued	1.9	1.7	9.3	5.6
Foreign currency translation adjustments	(15.7)	26.0	(16.5)	(13.7)
Cash flow hedges, net of tax	8.3	3.4	10.5	0.8
Defined benefit pension plans, net of tax	1.0	0.4	2.7	2.2
Stock-based compensation transactions, net of tax	5.3	3.9	25.5	19.9
Partial sale of business resulting in noncontrolling interest			1.5
Ending balance	1,577.6	1,330.0	1,577.6	1,330.0	$ 1,341.9
Accounting standards update [Extensible List]					Accounting Standards Update 2016-13
Cumulative effect adjustment
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance				(2.5)
Ending balance					$ (2.5)
Adjusted balance
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance				1,339.4
Ending balance					1,339.4
Retained Earnings
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	2,885.0	2,690.9	2,797.2	2,763.9
Net earnings	97.2	107.0	296.9	145.0
Dividends declared	(57.4)	(54.4)	(169.3)	(162.9)
Ending balance	2,924.8	2,743.5	2,924.8	2,743.5	2,763.9
Retained Earnings | Cumulative effect adjustment
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance				(2.5)
Ending balance					(2.5)
Retained Earnings | Adjusted balance
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance				2,761.4
Ending balance					2,761.4
Common Stock & Additional Contributed Capital
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	548.6	539.8	545.2	538.1
Dividends declared	1.3	1.4	3.9	4.1
Treasury stock issued	(0.5)	(4.1)	(20.2)	(21.1)
Stock-based compensation transactions, net of tax	5.3	3.9	25.5	19.9
Partial sale of business resulting in noncontrolling interest			0.3
Ending balance	554.7	541.0	554.7	541.0	538.1
Common Stock & Additional Contributed Capital | Adjusted balance
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance				538.1
Ending balance					538.1
Treasury Stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	(1,850.1)	(1,871.5)	(1,865.4)	(1,883.8)
Treasury stock purchased	(0.3)	(1.9)	(12.1)	(10.5)
Treasury stock issued	2.4	5.8	29.5	26.7
Ending balance	(1,848.0)	(1,867.6)	(1,848.0)	(1,867.6)	(1,883.8)
Treasury Stock | Adjusted balance
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance				(1,883.8)
Ending balance					(1,883.8)
Noncontrolling Interest
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	1.8	0.4	0.5	0.5
Net earnings		0.1	0.1	0.1
Foreign currency translation adjustments				(0.1)
Partial sale of business resulting in noncontrolling interest			1.2
Ending balance	1.8	0.5	1.8	0.5	0.5
Noncontrolling Interest | Adjusted balance
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance				0.5
Ending balance					0.5
Accumulated Other Comprehensive Income (Loss)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	(49.3)	(117.2)	(52.4)	(76.8)
Foreign currency translation adjustments	(15.7)	26.0	(16.5)	(13.6)
Cash flow hedges, net of tax	8.3	3.4	10.5	0.8
Defined benefit pension plans, net of tax	1.0	0.4	2.7	2.2
Ending balance	$ (55.7)	$ (87.4)	$ (55.7)	(87.4)	(76.8)
Accumulated Other Comprehensive Income (Loss) | Adjusted balance
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance				$ (76.8)
Ending balance					$ (76.8)