Pension And Other Postretirement Benefits (Schedule Of Changes In Fair Value Of Plan Assets) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan fair value of plan assets measured at net asset value	$ 680.7	$ 722.0
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Balance, beginning of year	722.0
Balance, end of year	680.7	722.0
Investments Measured at NAV [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan fair value of plan assets measured at net asset value	291.9	437.1
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Balance, beginning of year	437.1
Balance, end of year	291.9	437.1
Quoted Prices in Active Markets for Identical Inputs (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan fair value of plan assets measured at net asset value	76.0	97.2
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Balance, beginning of year	97.2
Balance, end of year	76.0	97.2
Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan fair value of plan assets measured at net asset value	279.7	162.5
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Balance, beginning of year	162.5
Balance, end of year	279.7	162.5
Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan fair value of plan assets measured at net asset value	33.1	25.2
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Balance, beginning of year	25.2	22.4
Realized gains	1.0
Unrealized gains	10.3	1.6
Purchases	0.1	2.5
Sales	(3.5)	(1.3)
Balance, end of year	33.1	25.2
Equity Securities - U.S.
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan fair value of plan assets measured at net asset value	40.9	47.9
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Balance, beginning of year	47.9
Balance, end of year	40.9	47.9
Equity Securities - U.S. | Investments Measured at NAV [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan fair value of plan assets measured at net asset value	13.6	17.3
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Balance, beginning of year	17.3
Balance, end of year	13.6	17.3
Equity Securities - U.S. | Quoted Prices in Active Markets for Identical Inputs (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan fair value of plan assets measured at net asset value	27.3	30.6
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Balance, beginning of year	30.6
Balance, end of year	27.3	30.6
Equity Securities - International
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan fair value of plan assets measured at net asset value	42.3	70.3
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Balance, beginning of year	70.3
Balance, end of year	42.3	70.3
Equity Securities - International | Investments Measured at NAV [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan fair value of plan assets measured at net asset value	13.9	24.9
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Balance, beginning of year	24.9
Balance, end of year	13.9	24.9
Equity Securities - International | Quoted Prices in Active Markets for Identical Inputs (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan fair value of plan assets measured at net asset value	28.4	45.4
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Balance, beginning of year	45.4
Balance, end of year	28.4	45.4
Fixed Income Investments
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan fair value of plan assets measured at net asset value	375.8	479.9
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Balance, beginning of year	479.9
Balance, end of year	375.8	479.9
Fixed Income Investments | Investments Measured at NAV [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan fair value of plan assets measured at net asset value	96.1	317.4
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Balance, beginning of year	317.4
Balance, end of year	96.1	317.4
Fixed Income Investments | Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan fair value of plan assets measured at net asset value	279.7	162.5
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Balance, beginning of year	162.5
Balance, end of year	279.7	162.5
Hedge Funds
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan fair value of plan assets measured at net asset value	41.8	36.0
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Balance, beginning of year	36.0
Balance, end of year	41.8	36.0
Hedge Funds | Investments Measured at NAV [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan fair value of plan assets measured at net asset value	41.8	36.0
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Balance, beginning of year	36.0
Balance, end of year	41.8	36.0
Real assets
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan fair value of plan assets measured at net asset value	36.7	34.8
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Balance, beginning of year	34.8
Balance, end of year	36.7	34.8
Real assets | Investments Measured at NAV [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan fair value of plan assets measured at net asset value	16.4	13.6
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Balance, beginning of year	13.6
Balance, end of year	16.4	13.6
Real assets | Quoted Prices in Active Markets for Identical Inputs (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan fair value of plan assets measured at net asset value	20.3	21.2
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Balance, beginning of year	21.2
Balance, end of year	20.3	21.2
Private Equity
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan fair value of plan assets measured at net asset value	29.9	15.8
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Balance, beginning of year	15.8
Balance, end of year	29.9	15.8
Private Equity | Investments Measured at NAV [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan fair value of plan assets measured at net asset value	8.2	2.0
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Balance, beginning of year	2.0
Balance, end of year	8.2	2.0
Private Equity | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan fair value of plan assets measured at net asset value	21.7	13.8
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Balance, beginning of year	13.8	11.0
Realized gains	0.8
Unrealized gains	9.2	1.0
Purchases	0.1	2.5
Sales	(2.2)	(0.7)
Balance, end of year	21.7	13.8
Other
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan fair value of plan assets measured at net asset value	31.5	33.5
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Balance, beginning of year	33.5
Balance, end of year	31.5	33.5
Other | Investments Measured at NAV [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan fair value of plan assets measured at net asset value	20.1	22.1
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Balance, beginning of year	22.1
Balance, end of year	20.1	22.1
Other | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan fair value of plan assets measured at net asset value	11.4	11.4
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Balance, beginning of year	11.4	11.4
Realized gains	0.2
Unrealized gains	1.1	0.6
Purchases
Sales	(1.3)	(0.6)
Balance, end of year	11.4	11.4
Short-term Investments
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan fair value of plan assets measured at net asset value	81.8	3.8
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Balance, beginning of year	3.8
Balance, end of year	81.8	3.8
Short-term Investments | Investments Measured at NAV [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan fair value of plan assets measured at net asset value	81.8	3.8
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Balance, beginning of year	3.8
Balance, end of year	$ 81.8	$ 3.8