Accounting for Stock-Based Compensation (Schedule of Share-based Compensation, Stock Options, Activity) (Details) (Employee Stock Option [Member], USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Mar. 31, 2013	Jun. 30, 2013
Employee Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Beginning Balance, shares	4,835,212	7,104,113	7,104,113
Exercised, Shares	(842,834)	(2,248,891)
Forfeited and Cancelled, Shares	(7,339)	(20,010)
Ending Balance, shares	3,985,039	4,835,212	3,985,039
Beginning of Period, Weighted Average Exercise Price	$ 34.98	$ 34.25	$ 34.25
Exercised, Weighted Average Exercise Price	$ 35.73	$ 32.53
Forfeited and Cancelled, Weighted Average Exercise Price	$ 33.39	$ 35.93
End of Period, Weighted Average Exercise Price	$ 34.80	$ 34.98	$ 34.80
Weighted Average Remaining Contractual Term			4 years 7 months 6 days
Aggregate Intrinsic Value	$ 48,119		$ 48,119
Exercisable, Shares	3,346,304		3,346,304
Exercisable, Weighted Average Exercise Price	$ 35.61		$ 35.61
Exercisable, Weighted Average Remaining Contractual Term			4 years
Exercisable, Aggregate Intrinsic Value	$ 37,698		$ 37,698