Income Taxes (Components Of Income Tax Expense (Benefit)) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Current
Federal	$ 270.6	$ 223.9	$ 256.7
State	33.2	28.2	31.3
Foreign	20.5	12.6	13.7
Income tax expense	324.3	264.7	301.7
Deferred
Federal	(33.1)	23.2	7.4
State	3.3	1.2	0.2
Foreign	0.0	1.2	0.4
Income tax expense	(29.8)	25.6	8.0
Total
Federal	237.5	247.1	264.1
State	36.5	29.4	31.5
Foreign	20.5	13.8	14.1
Income tax expense	$ 294.5	$ 290.3	$ 309.7