Pension And Other Postretirement Benefits Benefit Obligation (Narrative) (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Pension And Other Postretirement Benefits [Abstract]
Vesting percentage			100.00%
Required term of service to be eligible for plan match			one year of service and 1,000 hours of service
Award vesting period			3 years
Non-cash pension settlement charge			$ 17,700,000
Employer contributions	$ 20,000,000.0	$ 10,000,000.0	41,800,000	$ 11,700,000
Expected employer contributions remainder of year	$ 0		$ 0