CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (USD $) In Millions	Total	Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Income (Loss) [Member]	Retained Earnings [Member]	Treasury Stock
Balance at Beginning of Year at Dec. 31, 2011		$ 35.9	$ 2,591.1	$ 461.8	$ 6,611.0	$ (1,530.1)
Common Stock Activity			9.3
Other Comprehensive Income (Loss), Net of Tax	(6.4)			(6.4)
Net Income	213.9				213.9
Dividends to Stockholders (per common share: $0.130; $0.105)					(31.4)
Purchases of Treasury Stock						(175.2)
Balance at End of Period at Mar. 31, 2012	8,179.9	35.9	2,600.4	455.4	6,793.5	(1,705.3)
Balance at Beginning of Year at Dec. 31, 2012	8,612.6	36.0	2,607.7	628.0	7,371.6	(2,030.7)
Common Stock Activity			5.7
Other Comprehensive Income (Loss), Net of Tax	(142.3)			(142.3)
Net Income	212.6				212.6
Dividends to Stockholders (per common share: $0.130; $0.105)					(35.7)
Purchases of Treasury Stock						(95.1)
Balance at End of Period at Mar. 31, 2013	$ 8,557.8	$ 36.0	$ 2,613.4	$ 485.7	$ 7,548.5	$ (2,125.8)