Common Equity Common Equity 2 (Details) (USD $) In Millions, except Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 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	8,169,393		8,169,393
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price	$ 28.87		$ 28.87
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Number	5,253,148		5,253,148
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Exercise Price	$ 23.82		$ 23.82
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period, Total Intrinsic Value	$ 2.2	$ 11.6	$ 17.5	$ 36.0
Exercise of stock options			17.6	40.7
Employee Service Share-based Compensation, Tax Benefit Realized from Exercise of Stock Options			7.0	14.4
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			8,089,710
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	(96,791)		(802,622)
Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures in Period	(10,810)		(17,195)
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number	8,169,393	8,276,994	8,169,393	8,276,994
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price			$ 26.84
Share Based Compensation Arrangement By Share Based Payment Awards Options Exercises In Period Weighted Average Exercise Price	$ 24.07		$ 21.89
Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures and Expirations in Period, Weighted Average Exercise Price	$ 37.94		$ 36.73
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price	$ 28.87	$ 28.82	$ 28.87	$ 28.82
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	147.5		147.5
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Number	5,253,148		5,253,148
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Exercise Price	$ 23.82		$ 23.82
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	$ 121.3		$ 121.3