Consolidated Statements of Shareholders' Equity (Unaudited) - USD ($) $ in Millions	Total	Common Stock	Capital in Excess of Par Value	Retained Earnings	Accumulated Other Comprehensive Loss	Treasury Stock	Non-Controlling Interests
Balance, beginning of period at Dec. 31, 2018	$ 2,698.5	$ 1.2	$ 3,337.5	$ 3,157.7	$ (399.8)	$ (3,471.7)	$ 73.6
Balance, beginning of period (in shares) at Dec. 31, 2018		116,795,899
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net earnings (loss)	53.5			53.5
Other comprehensive income (loss)	(2.0)				(2.0)
Issuances under equity plans	(4.9)		0.4			(5.3)
Issuances under equity plans (in shares)		247,325
Share-based compensation expense	4.6		4.6
Repurchases of common stock	(101.0)					(101.0)
Noncontrolling interest transactions	1.2		0.5				0.7
Balance, end of period at Mar. 31, 2019	2,649.9	$ 1.2	3,343.0	3,211.2	(401.8)	(3,578.0)	74.3
Balance, end of period (in shares) at Mar. 31, 2019		117,043,224
Balance, beginning of period at Dec. 31, 2018	2,698.5	$ 1.2	3,337.5	3,157.7	(399.8)	(3,471.7)	73.6
Balance, beginning of period (in shares) at Dec. 31, 2018		116,795,899
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net earnings (loss)	326.9
Other comprehensive income (loss)	(52.7)
Balance, end of period at Sep. 30, 2019	2,716.1	$ 1.2	3,361.0	3,419.4	(452.5)	(3,631.0)	18.0
Balance, end of period (in shares) at Sep. 30, 2019		117,177,349
Balance, beginning of period at Mar. 31, 2019	2,649.9	$ 1.2	3,343.0	3,211.2	(401.8)	(3,578.0)	74.3
Balance, beginning of period (in shares) at Mar. 31, 2019		117,043,224
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net earnings (loss)	127.3			127.3
Other comprehensive income (loss)	(14.7)				(14.7)
Issuances under equity plans	2.0		3.9			(1.9)
Issuances under equity plans (in shares)		120,244
Share-based compensation expense	8.3		8.3
Dividends	(65.2)			(65.2)
Noncontrolling interest transactions	(13.1)		(0.8)				(12.3)
Balance, end of period at Jun. 30, 2019	2,694.5	$ 1.2	3,354.4	3,273.3	(416.5)	(3,579.9)	62.0
Balance, end of period (in shares) at Jun. 30, 2019		117,163,468
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net earnings (loss)	146.1			146.1
Other comprehensive income (loss)	(36.0)				(36.0)
Issuances under equity plans	0.6		0.7			(0.1)
Issuances under equity plans (in shares)		13,881
Share-based compensation expense	5.9		5.9
Repurchases of common stock	(51.0)					(51.0)
Noncontrolling interest transactions	(44.0)						(44.0)
Balance, end of period at Sep. 30, 2019	2,716.1	$ 1.2	3,361.0	3,419.4	(452.5)	(3,631.0)	18.0
Balance, end of period (in shares) at Sep. 30, 2019		117,177,349
Balance, beginning of period at Dec. 31, 2019	2,761.5	$ 1.2	3,370.6	3,494.1	(441.0)	(3,681.9)	18.5
Balance, beginning of period (in shares) at Dec. 31, 2019		117,190,883
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net earnings (loss)	1.7			1.7
Other comprehensive income (loss)	(64.8)				(64.8)
Issuances under equity plans	(0.5)		5.9			(6.4)
Issuances under equity plans (in shares)		293,298
Share-based compensation expense	4.6		4.6
Repurchases of common stock	(63.8)					(63.8)
Noncontrolling interest transactions	0.3						0.3
Balance, end of period at Mar. 31, 2020	2,639.0	$ 1.2	3,381.1	3,495.8	(505.8)	(3,752.1)	18.8
Balance, end of period (in shares) at Mar. 31, 2020		117,484,181
Balance, beginning of period at Dec. 31, 2019	2,761.5	$ 1.2	3,370.6	3,494.1	(441.0)	(3,681.9)	18.5
Balance, beginning of period (in shares) at Dec. 31, 2019		117,190,883
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net earnings (loss)	(52.4)
Other comprehensive income (loss)	8.2
Balance, end of period at Sep. 30, 2020	2,605.4	$ 1.2	3,395.1	3,378.5	(432.8)	(3,753.3)	16.7
Balance, end of period (in shares) at Sep. 30, 2020		117,543,804
Balance, beginning of period at Mar. 31, 2020	2,639.0	$ 1.2	3,381.1	3,495.8	(505.8)	(3,752.1)	18.8
Balance, beginning of period (in shares) at Mar. 31, 2020		117,484,181
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net earnings (loss)	(64.4)			(64.4)
Other comprehensive income (loss)	26.7				26.7
Issuances under equity plans	(0.2)					(0.2)
Issuances under equity plans (in shares)		14,898
Share-based compensation expense	6.9		6.9
Dividends	(63.2)			(63.2)
Noncontrolling interest transactions	(2.0)						(2.0)
Balance, end of period at Jun. 30, 2020	2,542.8	$ 1.2	3,388.0	3,368.2	(479.1)	(3,752.3)	16.8
Balance, end of period (in shares) at Jun. 30, 2020		117,499,079
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net earnings (loss)	10.3			10.3
Other comprehensive income (loss)	46.3				46.3
Issuances under equity plans	(0.8)		0.2			(1.0)
Issuances under equity plans (in shares)		44,725
Share-based compensation expense	6.9		6.9
Noncontrolling interest transactions	(0.1)						(0.1)
Balance, end of period at Sep. 30, 2020	$ 2,605.4	$ 1.2	$ 3,395.1	$ 3,378.5	$ (432.8)	$ (3,753.3)	$ 16.7
Balance, end of period (in shares) at Sep. 30, 2020		117,543,804