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			9 Months Ended
	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Sep. 30, 2013
Employee Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Beginning Balance, shares	3,985,039	4,835,212	7,104,113	7,104,113
Exercised, Shares	(143,670)	(842,834)	(2,248,891)
Forfeited and Cancelled, Shares	(23,683)	(7,339)	(20,010)
Ending Balance, shares	3,817,686	3,985,039	4,835,212	3,817,686
Beginning of Period, Weighted Average Exercise Price	$ 34.80	$ 34.98	$ 34.25	$ 34.25
Exercised, Weighted Average Exercise Price	$ 34.25	$ 35.73	$ 32.53
Forfeited and Cancelled, Weighted Average Exercise Price	$ 33.52	$ 33.39	$ 35.93
End of Period, Weighted Average Exercise Price	$ 34.83	$ 34.80	$ 34.98	$ 34.83
Weighted Average Remaining Contractual Term				4 years 4 months 24 days
Aggregate Intrinsic Value	$ 25,449			$ 25,449
Exercisable, Shares	3,237,644			3,237,644
Exercisable, Weighted Average Exercise Price	$ 35.53			$ 35.53
Exercisable, Weighted Average Remaining Contractual Term				3 years 8 months 12 days
Exercisable, Aggregate Intrinsic Value	$ 19,322			$ 19,322