Income Taxes (Schedule Of Gross Unrecognized Tax Benefits Reconciliation) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance of liability as of January 1	$ 39.8	$ 42.0	$ 46.4	$ 46.5
Increase as a result of tax positions taken during a prior year	1.1	4.6	2.5
Decrease as a result of tax positions taken during a prior year	(0.5)	(1.5)	(1.5)
Increase as a result of tax positions taken during the current year	3.2	3.1	5.2
Decrease as a result of settlements with taxing authorities	0.0	(1.1)	(0.3)
Reduction as a result of a lapse of the statute of limitations	(6.0)	(9.5)	(6.0)
Balance of liability as of December 31	$ 39.8	$ 42.0	$ 46.4	$ 46.5