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	693.9				693.9
Stock option exercises	88.9			88.9
Treasury stock sold	7.3			7.1				0.2
Currency translation adjustments	(28.6)						(28.6)
Stock-based compensation	86.4			86.4
Restricted stock activity	(16.4)			(16.4)
Dividends declared	(160.8)				(160.8)
Balance at end of period at Sep. 30, 2020	10,160.9		1.1	2,069.9	8,349.4		(241.4)	(18.1)
Balance at beginning of period at Jun. 30, 2020	9,879.7		1.1	2,012.9	8,168.7		(284.8)	(18.2)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net earnings	234.4				234.4
Stock option exercises	25.9			25.9				0.0
Treasury stock sold	2.8			2.7				0.1
Currency translation adjustments	43.4						43.4
Stock-based compensation	29.5			29.5
Restricted stock activity	(1.1)			(1.1)
Dividends declared	(53.7)				(53.7)
Balance at end of period at Sep. 30, 2020	10,160.9		1.1	2,069.9	8,349.4		(241.4)	(18.1)
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	864.8				864.8
Stock option exercises	81.8			81.8
Treasury stock sold	11.8			11.5				0.3
Currency translation adjustments	(3.5)						(3.5)
Stock-based compensation	103.3			103.3
Restricted stock activity	(17.9)			(17.9)
Dividends declared	(177.8)				(177.8)
Balance at end of period at Sep. 30, 2021	11,342.3		1.1	2,276.2	9,233.2		(150.5)	(17.7)
Balance at beginning of period at Jun. 30, 2021	11,089.2		1.1	2,217.9	9,003.1		(115.1)	(17.8)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net earnings	289.5				289.5
Stock option exercises	20.7			20.7
Treasury stock sold	3.6			3.5				0.1
Currency translation adjustments	(35.4)						(35.4)
Stock-based compensation	36.1			36.1
Restricted stock activity	(2.0)			(2.0)
Dividends declared	(59.4)				(59.4)
Balance at end of period at Sep. 30, 2021	$ 11,342.3		$ 1.1	$ 2,276.2	$ 9,233.2		$ (150.5)	$ (17.7)