Income Taxes (Schedule Of Income Tax Provision) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Income Tax Disclosure [Abstract]
Income before provision for income taxes	$ 367.6	$ 711.7	$ 1,260.9
Current provision for income taxes, Federal	97.1	152.7	217.9
Current provision for income taxes, State	20.2	28.5	38.6
Current provision for income taxes	117.3	181.2	256.5
Deferred provision for income taxes, Federal	(26.4)	(10.8)	36.7
Deferred provision for income taxes, State	(11.6)	3.1	7.9
Deferred provision for income taxes	(38.0)	(7.7)	44.6
Interest	2.2	2.4	1.5
Unrecognized Tax Benefits, Income Tax Penalties Expense	0.0	0.0	0.0
Interest and penalties expense (benefit)	2.2	2.4	1.5
Provision for income taxes	$ 81.5	$ 175.9	$ 302.6