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			9 Months Ended
	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Sep. 30, 2014
Employee Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Beginning Balance, shares	3,323,113	3,555,411	3,737,545	3,737,545
Exercised, Shares	(777,918)	(226,961)	(174,462)
Forfeited and Cancelled, Shares	(1,002)	(5,337)	(7,672)
Ending Balance, shares	2,544,193	3,323,113	3,555,411	2,544,193
Beginning of Period, Weighted Average Exercise Price	$ 34.71	$ 34.87	$ 34.88	$ 34.88
Exercised, Weighted Average Exercise Price	$ 35.75	$ 37.54	$ 35.01
Forfeited and Cancelled, Weighted Average Exercise Price	$ 18.99	$ 25.71	$ 34.61
End of Period, Weighted Average Exercise Price	$ 34.39	$ 34.71	$ 34.87	$ 34.39
Weighted Average Remaining Contractual Term				3 years 8 months 12 days
Aggregate Intrinsic Value	$ 52			$ 52
Exercisable, Shares	2,449,954			2,449,954
Exercisable, Weighted Average Exercise Price	$ 34.93			$ 34.93
Exercisable, Weighted Average Remaining Contractual Term				3 years 6 months
Exercisable, Aggregate Intrinsic Value	$ 49			$ 49