Stock-Based Compensation (Schedule Of Fair Value Of The Restricted Stock Awards Granted During The Periods) (Details) - Restricted Stock [Member] - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted			750,290	452,110
Estimated fair value (in millions)			$ 24.5	$ 23.3
Employees [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted	0	0	724,442	438,342
Estimated fair value (in millions)			$ 23.6	$ 22.4
Percentage of shares granted expected to be distributed			75.00%	90.00%
Non-employee Directors [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted	0	0	25,848	13,768
Estimated fair value (in millions)			$ 0.9	$ 0.9
Percentage of shares granted expected to be distributed			100.00%	100.00%