Condensed Consolidated Statements of Changes in Stockholders' Equity (unaudited) - USD ($) $ in Millions	Total	Cumulative Effect, Period of Adoption, Adjustment	Common stock	Additional paid-in capital	Retained earnings	Retained earnings Cumulative Effect, Period of Adoption, Adjustment	Accumulated other comprehensive loss	Treasury stock
Balance at beginning of period at Dec. 31, 2019	$ 9,491.9	$ (1.7)	$ 1.1	$ 1,903.9	$ 7,818.0	$ (1.7)	$ (212.8)	$ (18.3)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net earnings	459.5				459.5
Stock option exercises	63.0			63.0
Treasury stock sold	4.5			4.4				0.1
Currency translation adjustments	(72.0)						(72.0)
Stock-based compensation	56.9			56.9
Restricted stock activity	(15.3)			(15.3)
Dividends declared	(107.1)				(107.1)
Balance at end of period at Jun. 30, 2020	9,879.7		1.1	2,012.9	8,168.7		(284.8)	(18.2)
Balance at beginning of period at Mar. 31, 2020	9,591.3		1.1	1,946.3	8,003.1		(341.0)	(18.2)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net earnings	219.2				219.2
Stock option exercises	40.1			40.1
Treasury stock sold	1.7			1.7				0.0
Currency translation adjustments	56.2						56.2
Stock-based compensation	29.3			29.3
Restricted stock activity	(4.5)			(4.5)
Dividends declared	(53.6)				(53.6)
Balance at end of period at Jun. 30, 2020	9,879.7		1.1	2,012.9	8,168.7		(284.8)	(18.2)
Balance at beginning of period at Dec. 31, 2020	10,479.8		1.1	2,097.5	8,546.2		(147.0)	(18.0)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net earnings	575.3				575.3
Stock option exercises	61.1			61.1
Treasury stock sold	8.2			8.0				0.2
Currency translation adjustments	31.9						31.9
Stock-based compensation	67.2			67.2
Restricted stock activity	(15.9)			(15.9)
Dividends declared	(118.4)				(118.4)
Balance at end of period at Jun. 30, 2021	11,089.2		1.1	2,217.9	9,003.1		(115.1)	(17.8)
Balance at beginning of period at Mar. 31, 2021	10,765.7		1.1	2,138.9	8,776.0		(132.4)	(17.9)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net earnings	286.3				286.3
Stock option exercises	41.9			41.9
Treasury stock sold	3.5			3.4				0.1
Currency translation adjustments	17.3						17.3
Stock-based compensation	34.8			34.8
Restricted stock activity	(1.1)			(1.1)
Dividends declared	(59.2)				(59.2)
Balance at end of period at Jun. 30, 2021	$ 11,089.2		$ 1.1	$ 2,217.9	$ 9,003.1		$ (115.1)	$ (17.8)