Share-Based Compensation (Summary Of Compensation Expense) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Share-Based Compensation Arrangement By Share-based Payment Award [Line Items]
Share-based compensation	$ 9.1	$ 14.2	$ 16.5
Stock appreciation rights
Share-Based Compensation Arrangement By Share-based Payment Award [Line Items]
Share-based compensation	4.4	5.5	6.1
Performance Shares
Share-Based Compensation Arrangement By Share-based Payment Award [Line Items]
Share-based compensation	0.5	0.7	0.3
Restricted stock units
Share-Based Compensation Arrangement By Share-based Payment Award [Line Items]
Share-based compensation	$ 4.2	$ 8.0	$ 10.1