Earnings Per Share (EPS) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended		1 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012	Apr. 30, 2012 Exchangeable Senior Notes [Member]
Weighted-average number of basic shares	297.5	309.2	298.1	304.2
Shares issuable under incentive stock plans	3.7	3.5	3.8	3.2
Exchangeable Senior Notes	0	1.7	0	6.1
Weighted average number of diluted shares	301.2	314.4	301.9	313.5
Anti-dilutive shares	1.1	5.8	1.4	6.4
Settlement of Exchangeable Senior Notes				$ (4.5)	$ 357.0
Shares issued for settlement of Exchangeable Senior Notes, in millions, shares					10.8