Condensed Consolidated Statements of Stockholders' Equity (Deficit) - USD ($) $ in Millions	Total	Common Stock	Additional Paid-in Capital	Retained Earnings	Common Stock in Treasury	Accumulated Other Comprehensive Loss, Net of Taxes
Balance at beginning of period at Dec. 31, 2019	$ (196.2)	$ 23.2	$ 2,073.5	$ 1,998.5	$ (3,382.4)	$ (909.0)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Effect of share-based incentive compensation	9.1		9.1
Stock issued for profit sharing contribution paid in stock	24.4		(11.7)		36.1
Recognition of pension items, net of taxes	2.1					2.1
Foreign currency translation adjustments	(87.1)					(87.1)
Unrealized (loss) gain on derivative instruments, net of taxes	1.0					1.0
Net earnings	226.7			226.7
Dividends on common stock	(50.1)			(50.1)
Balance at end of period at Jun. 30, 2020	(70.1)	23.2	2,070.9	2,175.1	(3,346.3)	(993.0)
Balance at beginning of period at Mar. 31, 2020	(181.9)	23.2	2,059.6	2,099.9	(3,346.3)	(1,018.3)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Effect of share-based incentive compensation	11.3		11.3
Recognition of pension items, net of taxes	1.1					1.1
Foreign currency translation adjustments	32.2					32.2
Unrealized (loss) gain on derivative instruments, net of taxes	(8.0)					(8.0)
Net earnings	100.1			100.1
Dividends on common stock	(24.9)			(24.9)
Balance at end of period at Jun. 30, 2020	(70.1)	23.2	2,070.9	2,175.1	(3,346.3)	(993.0)
Balance at beginning of period at Dec. 31, 2020	172.5	23.2	2,093.0	2,400.7	(3,380.9)	(963.5)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Effect of share-based incentive compensation	10.5		10.5
Stock issued for profit sharing contribution paid in stock	28.0		0.2		27.8
Repurchases of common stock	(298.0)				(298.0)
Recognition of pension items, net of taxes	1.5					1.5
Foreign currency translation adjustments	2.0					2.0
Unrealized (loss) gain on derivative instruments, net of taxes	15.2					15.2
Net earnings	218.2			218.2
Dividends on common stock	(56.1)			(56.1)
Balance at end of period at Jun. 30, 2021	93.8	23.2	2,103.7	2,562.8	(3,651.1)	(944.8)
Balance at beginning of period at Mar. 31, 2021	101.4	23.2	2,090.8	2,485.6	(3,528.6)	(969.6)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Effect of share-based incentive compensation	12.9		12.9
Repurchases of common stock	(122.5)				(122.5)
Recognition of pension items, net of taxes	1.7					1.7
Foreign currency translation adjustments	27.2					27.2
Unrealized (loss) gain on derivative instruments, net of taxes	(4.1)					(4.1)
Net earnings	108.1			108.1
Dividends on common stock	(30.9)			(30.9)
Balance at end of period at Jun. 30, 2021	$ 93.8	$ 23.2	$ 2,103.7	$ 2,562.8	$ (3,651.1)	$ (944.8)