Condensed Consolidated Statements of Changes in Stockholders' Equity (unaudited) - USD ($) $ in Millions	Total	Common stock	Additional paid-in capital	Retained earnings	Accumulated other comprehensive loss	Treasury stock
Balance at Dec. 31, 2017	$ 6,863.6	$ 1.0	$ 1,602.9	$ 5,464.6	$ (186.2)	$ (18.7)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net earnings	211.3			211.3
Stock option exercises	29.1		29.1
Treasury stock sold	1.6		1.5			0.1
Currency translation adjustments	57.8				57.8
Stock-based compensation	25.7		25.7
Restricted stock activity	(5.3)		(5.3)
Dividends declared ($0.4625 per share)	(42.6)			(42.6)
Balance at Mar. 31, 2018	7,155.5	1.0	1,653.9	5,647.6	(128.4)	(18.6)
Balance at Dec. 31, 2018	7,738.5	1.1	1,751.5	6,247.7	(243.3)	(18.5)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net earnings	369.6			369.6
Stock option exercises	36.8		36.8
Treasury stock sold	2.2		2.1			0.1
Currency translation adjustments	28.7				28.7
Stock-based compensation	24.3		24.3
Restricted stock activity	(14.8)		(14.8)
Dividends declared ($0.4625 per share)	(47.9)			(47.9)
Balance at Mar. 31, 2019	$ 8,137.4	$ 1.1	$ 1,799.9	$ 6,569.4	$ (214.6)	$ (18.4)