Equity (Components of Shareholders' Equity) (Details) - USD ($) $ in Millions	3 Months Ended						9 Months Ended
	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2020	Sep. 30, 2019
Payments for Repurchase of Common Stock							$ 0.0	$ 500.1
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	$ 5,959.5	$ 5,789.8	$ 7,312.4	$ 7,172.9	$ 6,922.8	$ 7,064.8	7,312.4	7,064.8
Net earnings	404.6	242.1	(25.9)	463.4	460.3	203.7	620.8	1,127.4
Pension and OPEB adjustments, net of tax	1.9			12.6			(2.2)	34.5
Total comprehensive income (loss)	519.6			332.3			729.2	1,022.8
Share-based compensation	11.6	16.0	27.6	13.1	10.2	29.0
Dividends declared to noncontrolling interests	(12.2)		(6.1)	(5.0)		(9.3)
Shares issued under incentive plans, net	(35.5)	(3.7)		(15.2)	(14.9)	(6.3)
Repurchase of ordinary shares				(250.1)		(250.0)
Ending balance	6,381.0	5,959.5	5,789.8	7,279.1	7,172.9	6,922.8	6,381.0	7,279.1
Other				(0.1)		(0.1)
Noncontrolling Interests
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	22.6	17.2	44.8	42.4	37.0	42.1	44.8	42.1
Net earnings	4.0	3.3	3.3	4.6	4.2	3.8
Dividends declared to noncontrolling interests	(12.2)		(6.1)	(5.0)		(9.3)
Ending balance	$ 14.3	$ 22.6	$ 17.2	$ 41.5	$ 42.4	$ 37.0	$ 14.3	$ 41.5