Earnings Per Share (Changes In Stock Price Impact On Number Of Shares Included In Diluted Earnings Per Share And Issuable Upon Conversion Of Notes) (Details) (USD $)	9 Months Ended
	Sep. 30, 2013
Earning Per Share [Line Items]
Percent of Senior Convertible Notes	1.875%
80.73 [Member]
Earning Per Share [Line Items]
Share Price	$ 80.73
Conversion of stock, shares converted	(4,310)	[1]
Total Treasury Method Incremental Shares	61,766	[2]
80.73 [Member] | Shares Underlying 1.875% Convertible Notes [Member]
Earning Per Share [Line Items]
Conversion of stock, shares converted	61,766
80.73 [Member] | Shares Due To The Company Under Notes Hedges [Member]
Earning Per Share [Line Items]
Total Treasury Method Incremental Shares	(66,076)
90.73 [Member]
Earning Per Share [Line Items]
Share Price	$ 90.73
Conversion of stock, shares converted	(22,118)	[1]
Total Treasury Method Incremental Shares	317,009	[2]
90.73 [Member] | Shares Underlying 1.875% Convertible Notes [Member]
Earning Per Share [Line Items]
Conversion of stock, shares converted	317,009
90.73 [Member] | Shares Due To The Company Under Notes Hedges [Member]
Earning Per Share [Line Items]
Total Treasury Method Incremental Shares	(339,127)
100.73 [Member]
Earning Per Share [Line Items]
Share Price	$ 100.73
Conversion of stock, shares converted	(36,391)	[1]
Total Treasury Method Incremental Shares	521,573	[2]
100.73 [Member] | Shares Underlying 1.875% Convertible Notes [Member]
Earning Per Share [Line Items]
Conversion of stock, shares converted	521,573
100.73 [Member] | Shares Due To The Company Under Notes Hedges [Member]
Earning Per Share [Line Items]
Total Treasury Method Incremental Shares	(557,964)
110.73 [Member]
Earning Per Share [Line Items]
Share Price	$ 110.73
Conversion of stock, shares converted	73,426	[1]
Warrant Shares	121,511
Total Treasury Method Incremental Shares	810,700	[2]
110.73 [Member] | Shares Underlying 1.875% Convertible Notes [Member]
Earning Per Share [Line Items]
Conversion of stock, shares converted	689,189
110.73 [Member] | Shares Due To The Company Under Notes Hedges [Member]
Earning Per Share [Line Items]
Total Treasury Method Incremental Shares	(737,274)
120.73 [Member]
Earning Per Share [Line Items]
Share Price	$ 120.73
Conversion of stock, shares converted	264,279	[1]
Warrant Shares	322,121
Total Treasury Method Incremental Shares	1,151,159	[2]
120.73 [Member] | Shares Underlying 1.875% Convertible Notes [Member]
Earning Per Share [Line Items]
Conversion of stock, shares converted	829,038
120.73 [Member] | Shares Due To The Company Under Notes Hedges [Member]
Earning Per Share [Line Items]
Total Treasury Method Incremental Shares	(886,880)
130.73 [Member]
Earning Per Share [Line Items]
Share Price	$ 130.73
Conversion of stock, shares converted	425,933	[1]
Warrant Shares	492,040
Total Treasury Method Incremental Shares	1,439,532	[2]
130.73 [Member] | Shares Underlying 1.875% Convertible Notes [Member]
Earning Per Share [Line Items]
Conversion of stock, shares converted	947,492
130.73 [Member] | Shares Due To The Company Under Notes Hedges [Member]
Earning Per Share [Line Items]
Total Treasury Method Incremental Shares	(1,013,599)

[1] Represents the number of incremental shares to be issued by the Company upon conversion of the 1.875% Convertible Notes, assuming concurrent settlement of the note hedges and warrants.

[2] Represents the number of incremental shares that must be included in the calculation of fully diluted shares under U.S. GAAP.