Pension And Other Postretirement Benefits (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended		12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Defined Benefit Plan Disclosure [Line Items]
Required term of service to be eligible for plan match					1 year 1000 hours
Defined Benefit Plan, Ultimate Health Care Cost Trend Rate, Actuarial Present Value	5.00%				5.00%
Estimated nonqualified benefits in next fiscal year					$ 2.0
Non-cash pension settlement charge					30.4	$ 27.7
Estimated future employer contributions	$ 40.0				40.0
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Discount Rate	2.72%	2.72%	2.62%	3.38%			4.31%
Non-cash pension settlement charge					30.4	27.7
Accumulated benefit obligation	$ 774.7	$ 844.0			$ 774.7	$ 844.0
Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Discount Rate					2.22%	3.19%	4.16%
Healthcare cost trend on covered charges					5.00%	5.00%	5.00%