Income Taxes (Unrecognized Tax Benefits And Associated Interest And Penalties) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Federal, State and Foreign Tax
Unrecognized Tax Benefits [Roll Forward]
Unrecognized tax benefits, beginning balance	$ 90.4	$ 16.6
Reductions for tax positions related to prior years	(11.5)	(13.6)
Additions for tax positions related to current year	21.1	39.5
Reductions for tax positions due to settlements	(9.0)	(0.2)
Additions for tax positions related to purchase accounting		48.1
Unrecognized tax benefits, ending balance	91.0	90.4
Accrued Interest and Penalties
Unrecognized Tax Benefits [Roll Forward]
Unrecognized tax benefits, beginning balance	5.9	0.0
Unrecognized tax benefits, ending balance	$ 2.8	$ 5.9