Accounting for Stock-Based Compensation (Schedule of Share-based Compensation, Stock Options, Activity) (Details) (Employee Stock Option [Member], USD $) In Millions, except Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Mar. 31, 2014	Jun. 30, 2014
Employee Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Beginning Balance, shares	3,555,411	3,737,545	3,737,545
Exercised, Shares	(226,961)	(174,462)
Forfeited and Cancelled, Shares	(5,337)	(7,672)
Ending Balance, shares	3,323,113	3,555,411	3,323,113
Beginning of Period, Weighted Average Exercise Price	$ 34.87	$ 34.88	$ 34.88
Exercised, Weighted Average Exercise Price	$ 37.54	$ 35.01
Forfeited and Cancelled, Weighted Average Exercise Price	$ 25.71	$ 34.61
End of Period, Weighted Average Exercise Price	$ 34.71	$ 34.87	$ 34.71
Weighted Average Remaining Contractual Term			3 years 8 months 12 days
Aggregate Intrinsic Value	$ 35		$ 35
Exercisable, Shares	3,207,858		3,207,858
Exercisable, Weighted Average Exercise Price	$ 35.23		$ 35.23
Exercisable, Weighted Average Remaining Contractual Term			3 years 6 months
Exercisable, Aggregate Intrinsic Value	$ 33		$ 33