Pension And Other Postretirement Benefits Benefit Obligation (Schedule Of Net Funded Status) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Balance, beginning of year	$ 508.2
Balance, end of year	481.8	$ 508.2
Paid from Company assets for unfunded nonqualified benefits	1.1	3.9
Pension Benefits [Member]
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit obligation, beginning of period	616.8	577.9
Service cost	22.6	24.3	$ 26.4
Interest cost	31.9	31.9	25.5
Actuarial loss (gain)	(7.9)	36.8
Benefits paid from plan assets	(47.0)	(44.7)
Benefits paid from Company assets	(1.0)	(3.9)
Plan participants' contributions
Administrative expenses paid	(1.6)	(5.5)
Benefit obligation, end of period	613.8	616.8	577.9
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Balance, beginning of year	508.2	433.1
Actual return on plan assets	(17.8)	25.3
Employer contributions	41.1	103.9
Plan participants' contributions
Benefits paid	(48.1)	(48.6)
Administrative expenses paid	(1.6)	(5.5)
Balance, end of year	481.8	508.2	433.1
Unfunded status	132.0	108.6
Postretirement Benefits [Member]
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit obligation, beginning of period	62.4	62.3
Service cost	1.4	1.4	2.0
Interest cost	3.2	3.4	2.0
Actuarial loss (gain)	(1.8)
Benefits paid from plan assets
Benefits paid from Company assets	(4.2)	(4.8)
Plan participants' contributions		0.1
Administrative expenses paid
Benefit obligation, end of period	61.0	62.4	62.3
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Balance, beginning of year
Actual return on plan assets
Employer contributions	4.2	4.7
Plan participants' contributions		0.1
Benefits paid	(4.2)	(4.8)
Administrative expenses paid
Balance, end of year
Unfunded status	$ 61.0	$ 62.4