Income Taxes (Schedule Of Provision For Income Taxes) (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Tax Contingency [Line Items]
Tax Cuts And Jobs Act Of 2017, Incomplete Accounting, Provisional Income Tax Expense (Benefit)	$ 87.0	$ (4.8)
Current, U.S. federal tax		9.3	$ 58.4	$ 38.7
Current, state and local tax		4.9	5.0	5.1
Current, Non-U.S. tax		14.0	29.3	21.6
Total current		28.2	92.7	65.4
Deferred, U.S. federal tax		35.7	99.2	(28.0)
Deferred, U.S. state and local tax		2.0	0.1	1.5
Deferred, Non-U.S. tax		10.0	3.0	1.4
Total deferred		47.7	102.3	(25.1)
Total provision for income taxes		75.9	$ 195.0	$ 40.3
Tax Cut and Jobs Act Tax [Domain]
Income Tax Contingency [Line Items]
Tax Cuts And Jobs Act Of 2017, Incomplete Accounting, Provisional Income Tax Expense (Benefit)	75.0	(5.1)
Toll Tax [Domain]
Income Tax Contingency [Line Items]
Tax Cuts And Jobs Act Of 2017, Incomplete Accounting, Provisional Income Tax Expense (Benefit)	8.0	0.7
Assertion Tax [Domain]
Income Tax Contingency [Line Items]
Tax Cuts And Jobs Act Of 2017, Incomplete Accounting, Provisional Income Tax Expense (Benefit)	$ 4.0	$ (0.4)