Income Taxes (Schedule Of The Reconciliation To U.S. Statutory Tax Rate) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Continuing operations tax at statutory rate	$ 77.7	$ 52.7	$ 33.1
Increase in valuation allowances on deferred domestic income tax assets	9.1	0.8	4.1
State income tax expense, net of federal benefit	7.9	3.2	4.0
Separation costs		15.1
Domestic production activities	(5.8)	(1.9)	(5.2)
Federal statute closure	(2.3)	(15.2)
2017 Tax Act	(82.5)
Other	(2.6)	(3.4)	0.7
Income tax expense (benefit)	$ 1.5	$ 51.3	$ 36.7