Equity (Components of Shareholders' Equity) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended									36 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012		Sep. 30, 2011	Sep. 30, 2012 Shareholders' Equity [Member]		Sep. 30, 2011 Shareholders' Equity [Member]	Sep. 30, 2012 Noncontrolling Interest [Member]		Sep. 30, 2011 Noncontrolling Interest [Member]	Dec. 31, 2011 Immaterial Reclassification Adjustment [Member] Noncontrolling Interest [Member]
Balance at December 31:			$ 7,012.4		$ 8,059.1	$ 6,924.3		$ 7,964.3	$ 88.1		$ 94.8
Net earnings	327.0	93.5	802.2		121.2	783.0		100.9	19.2		20.3
Currency translation			48.1	[1]	(38.9)	58.4	[1]	(38.9)	(10.3)	[1]	0	11.5	[1]
Change in value of marketable securities and derivatives qualifying as cash flow hedges, net of tax			5.2		1.3	5.2		1.3	0		0
Pension and OPEB adjustments, net of tax			57.0		91.8	58.3		92.4	(1.3)		(0.6)
Total comprehensive income (loss)	485.7	(137.3)	912.5		175.4	904.9		155.7	7.6		19.7
Share-based compensation			34.7		31.0	34.7		31.0	0		0
Settlement of Exchangeable Senior Notes			(4.5)			(4.5)			0
Acquisition/divestiture of noncontrolling interests			(0.4)		(2.5)	(1.2)		(1.3)	0.8		(1.2)
Dividends to noncontrolling interests			(12.3)		(22.9)	0		0	(12.3)		(22.9)
Dividends to ordinary shareholders			(98.5)		(101.5)	(98.5)		(101.5)	0		0
Accretion of Exchangeable Senior Notes from Temporary Equity			3.3		10.0	3.3		10.0	0		0
Shares issued under incentive plans, net			57.7		107.4	57.7		107.4	0		0
Repurchase of ordinary shares			(374.9)		(575.6)	(374.9)		(575.6)	0		0
Other					(1.7)			(0.7)			(1.0)
Balance at September 30:	$ 7,530.0	$ 7,678.7	$ 7,530.0		$ 7,678.7	$ 7,445.8		$ 7,589.3	$ 84.2		$ 89.4

[1] During the third quarter of 2012, the Company reclassified a $11.5 million currency translation loss to Noncontrolling interests from IR-Ireland shareholders' equity related to activity from prior to 2012. This reclassification corrects the allocation of currency translation gains (losses) between the Equity components. The Company does not believe this reclassification adjustment is material to 2012 or to any of its previously issued annual or interim financial statements.