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
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018	Dec. 31, 2017
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	$ 1,238.8	$ 1,128.6	$ 1,157.6	$ 1,190.8
Effect of accounting change on prior years					$ 0.1	$ (2.3)
Adjusted beginning balance					1,157.7	1,188.5
Net earnings	99.6	90.0	247.0	253.0
Dividends declared (See Note 7)	(52.6)	(49.5)	(155.0)	(146.2)
Dividends paid to noncontrolling interest	(0.2)		(0.2)	(0.2)
Treasury stock purchased	(7.4)	(5.4)	(19.9)	(113.2)
Treasury stock issued	6.6	7.2	23.5	14.2
Foreign currency translation adjustments	(32.9)	(10.9)	(23.1)	(50.0)
Cash flow hedges, net of tax	(1.2)	0.6	3.4	(0.7)
Defined benefit pension plans, net of tax	0.5	0.4	1.5	1.5
Stock-based compensation transactions, net of tax	4.4	5.0	20.7	19.1
Ending balance	1,255.6	1,166.0	1,255.6	1,166.0
Retained Earnings
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	2,656.2	2,572.6	2,613.8	2,511.3
Effect of accounting change on prior years					0.1	(2.3)
Adjusted beginning balance					2,613.9	2,509.0
Net earnings	99.6	90.0	247.0	252.9
Dividends declared (See Note 7)	(54.0)	(50.9)	(159.1)	(150.2)
Ending balance	2,701.8	2,611.7	2,701.8	2,611.7
Common Stock & Additional Contributed Capital
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	532.1	521.7	529.1	516.7
Adjusted beginning balance					529.1	516.7
Dividends declared (See Note 7)	1.4	1.4	4.1	4.0
Treasury stock issued	(4.5)	(4.4)	(20.5)	(16.1)
Stock-based compensation transactions, net of tax	4.4	5.0	20.7	19.1
Ending balance	533.4	523.7	533.4	523.7
Treasury Stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	(1,887.9)	(1,917.4)	(1,908.3)	(1,828.3)
Adjusted beginning balance					(1,908.3)	(1,828.3)
Treasury stock purchased	(7.4)	(5.4)	(19.9)	(113.2)
Treasury stock issued	11.1	11.6	44.0	30.3
Ending balance	(1,884.2)	(1,911.2)	(1,884.2)	(1,911.2)
Noncontrolling Interest
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	0.6	0.4	0.6	0.6
Adjusted beginning balance					0.6	0.6
Net earnings	0.0	0.0		0.1
Dividends paid to noncontrolling interest	(0.2)		(0.2)	(0.2)
Foreign currency translation adjustments		0.1		0.0
Ending balance	0.4	0.5	0.4	0.5
Accumulated Other Comprehensive Income (Loss)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	(62.2)	(48.7)	(77.6)	(9.5)
Adjusted beginning balance					$ (77.6)	$ (9.5)
Foreign currency translation adjustments	(32.9)	(11.0)	(23.1)	(50.0)
Cash flow hedges, net of tax	(1.2)	0.6	3.4	(0.7)
Defined benefit pension plans, net of tax	0.5	0.4	1.5	1.5
Ending balance	$ (95.8)	$ (58.7)	$ (95.8)	$ (58.7)