Employee Benefit Plans (Narrative) (Details) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020 USD ($) pension_plan	Sep. 30, 2019 USD ($)	Sep. 30, 2020 USD ($) pension_plan	Sep. 30, 2019 USD ($)
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Contribution Plan, Cost | $	$ 2.8	$ 2.8	$ 9.7	$ 9.3
Number Of Sponsored Pension Plans | pension_plan	2		2
Number Of Sponsored Pension Plans, Non-Union Employees | pension_plan	1		1
Number Of Sponsored Pension Plans, Union Employees | pension_plan	1		1
Pension Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Expected Future Employer Contributions, Next Fiscal Year | $	$ 29.3		$ 29.3
Other Postretirement Benefits Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Expected Future Employer Contributions, Next Fiscal Year | $	$ 0.9		$ 0.9