Common Equity Common Equity 2 (Details) (USD $) In Millions, except Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number	7,571,752		7,571,752
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price	$ 29.27		$ 29.27
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Number	4,691,897		4,691,897
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Exercise Price	$ 23.95		$ 23.95
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period, Total Intrinsic Value	$ 12.7	$ 1.9	$ 30.2	$ 37.9
Exercise of stock options			31.7	42.7
Employee Service Share-based Compensation, Tax Benefit Realized from Exercise of Stock Options			12.1	15.1
Stock options [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number	8,169,393		8,089,710
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period	0		899,500	1,418,560
Share Based Compensation Arrangement By Share Based Payment Award Options Grant In Period Weighted Average Exercise Price	$ 0.00		$ 41.03
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period	(597,641)		(1,400,263)
Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures in Period	0		(17,195)
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number	7,571,752		7,571,752
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price	$ 28.87		$ 26.84
Share Based Compensation Arrangement By Share Based Payment Awards Options Exercises In Period Weighted Average Exercise Price	$ 23.69		$ 22.66
Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures and Expirations in Period, Weighted Average Exercise Price	$ 0.00		$ 36.73
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price	$ 29.27		$ 29.27
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range Outstanding Options Weighted Average Remaining Contractual Period			5 years 7 months
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Intrinsic Value	103.9		103.9
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Number	4,691,897		4,691,897
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Exercise Price	$ 23.95		$ 23.95
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Exercisable Options, Weighted Average Remaining Contractual Term			3 years 11 months
Share Based Compensation Arrangement by Share Based Payments Award, Options Exercisable, Intrinsic Value	$ 89.4		$ 89.4