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
	Jan. 01, 2020	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019	Dec. 31, 2018
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	$ 1,312.5	$ 1,214.6	$ 1,238.8	$ 1,312.5	$ 1,157.6	$ 1,157.6
Net earnings		104.9	99.6	144.5	247.0
Dividends declared		(53.0)	(52.6)	(158.8)	(155.0)
Dividends paid to noncontrolling interest			(0.2)		(0.2)
Treasury stock purchased		(1.9)	(7.4)	(10.5)	(19.9)
Treasury stock issued		1.7	6.6	5.6	23.5
Foreign currency translation adjustments		26.0	(32.9)	(13.7)	(23.1)
Cash flow hedges, net of tax		3.4	(1.2)	0.8	3.4
Defined benefit pension plans, net of tax		0.4	0.5	2.2	1.5
Stock-based compensation transactions, net of tax		3.9	4.4	19.9	20.7
Ending balance		1,300.0	1,255.6	1,300.0	1,255.6	$ 1,312.5	$ 1,157.6
Accounting Standards Update [Extensible List]	us-gaap:AccountingStandardsUpdate201613Member					us-gaap:AccountingStandardsUpdate201613Member	us-gaap:AccountingStandardsUpdate201602Member
Cumulative effect adjustment
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	$ (2.5)			(2.5)	0.1	$ 0.1
Ending balance						(2.5)	$ 0.1
Adjusted balance
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	1,310.0			1,310.0	1,157.7	1,157.7
Ending balance						1,310.0	1,157.7
Retained Earnings
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	2,734.5	2,663.1	2,656.2	2,734.5	2,613.8	2,613.8
Net earnings		104.8	99.6	144.4	247.0
Dividends declared		(54.4)	(54.0)	(162.9)	(159.1)
Ending balance		2,713.5	2,701.8	2,713.5	2,701.8	2,734.5	2,613.8
Retained Earnings | Cumulative effect adjustment
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	(2.5)			(2.5)	0.1	0.1
Ending balance						(2.5)	0.1
Retained Earnings | Adjusted balance
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	2,732.0			2,732.0	2,613.9	2,613.9
Ending balance						2,732.0	2,613.9
Common Stock & Additional Contributed Capital
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	538.1	539.8	532.1	538.1	529.1	529.1
Dividends declared		1.4	1.4	4.1	4.1
Treasury stock issued		(4.1)	(4.5)	(21.1)	(20.5)
Stock-based compensation transactions, net of tax		3.9	4.4	19.9	20.7
Ending balance		541.0	533.4	541.0	533.4	538.1	529.1
Common Stock & Additional Contributed Capital | Adjusted balance
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	538.1			538.1	529.1	529.1
Ending balance						538.1	529.1
Treasury Stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	(1,883.8)	(1,871.5)	(1,887.9)	(1,883.8)	(1,908.3)	(1,908.3)
Treasury stock purchased		(1.9)	(7.4)	(10.5)	(19.9)
Treasury stock issued		5.8	11.1	26.7	44.0
Ending balance		(1,867.6)	(1,884.2)	(1,867.6)	(1,884.2)	(1,883.8)	(1,908.3)
Treasury Stock | Adjusted balance
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	(1,883.8)			(1,883.8)	(1,908.3)	(1,908.3)
Ending balance						(1,883.8)	(1,908.3)
Noncontrolling Interest
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	0.5	0.4	0.6	0.5	0.6	0.6
Net earnings		0.1		0.1
Dividends paid to noncontrolling interest			(0.2)		(0.2)
Foreign currency translation adjustments				(0.1)
Ending balance		0.5	0.4	0.5	0.4	0.5	0.6
Noncontrolling Interest | Adjusted balance
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	0.5			0.5	0.6	0.6
Ending balance						0.5	0.6
Accumulated Other Comprehensive Income (Loss)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	(76.8)	(117.2)	(62.2)	(76.8)	(77.6)	(77.6)
Foreign currency translation adjustments		26.0	(32.9)	(13.6)	(23.1)
Cash flow hedges, net of tax		3.4	(1.2)	0.8	3.4
Defined benefit pension plans, net of tax		0.4	0.5	2.2	1.5
Ending balance		$ (87.4)	$ (95.8)	(87.4)	(95.8)	(76.8)	(77.6)
Accumulated Other Comprehensive Income (Loss) | Adjusted balance
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	$ (76.8)			$ (76.8)	$ (77.6)	(77.6)
Ending balance						$ (76.8)	$ (77.6)