Earnings (Loss) Per Common Share (Impact Of Company's Stock Price On Assuming Dilution Calculation For The Subordinated Convertible Notes) (Details) (Subordinated Convertible Notes Due 2029 [Member], USD $)	9 Months Ended
	Sep. 30, 2011
Share price	$ 36.75
Changes In The Company's Stock Price - 1 [Member]
Share price	$ 36.75
Changes In The Company's Stock Price - 2 [Member]
Share price	$ 38.75
Shares Underlying Subordinated Convertible Notes	603,152
Total Treasury Method Incremental Shares	603,152	[1]
Changes In The Company's Stock Price - 3 [Member]
Share price	$ 40.75
Shares Underlying Subordinated Convertible Notes	1,147,099
Total Treasury Method Incremental Shares	1,147,099	[1]
Changes In The Company's Stock Price - 4 [Member]
Share price	$ 42.75
Shares Underlying Subordinated Convertible Notes	1,640,151
Total Treasury Method Incremental Shares	1,640,151	[1]
Changes In The Company's Stock Price - 5 [Member]
Share price	$ 44.75
Shares Underlying Subordinated Convertible Notes	2,089,131
Total Treasury Method Incremental Shares	2,089,131	[1]

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