Basis of Presentation Employee Benefits (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Contributions by Employer			$ 11.5
Defined Benefit Plan, Expected Future Employer Contributions, Remainder of Fiscal Year	$ 2.3		2.3
WRAP Plan Liabilities	25.0		25.0		$ 26.8
Rabbi Trust Marketable Securities	23.6		23.6		$ 23.1
Deferred Compensation Mark To Market Adjustments	0.5	$ (3.1)	(2.7)	$ 0.6
Marketable Securities, Unrealized Gain (Loss)	(1.1)	$ (0.1)	(1.1)	$ (2.8)
Pension Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Contributions by Employer			4.0
SERP [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Contributions by Employer			7.5
Defined Benefit Plan, Expected Future Employer Contributions, Remainder of Fiscal Year	2.2		2.2
Medical Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Expected Future Employer Contributions, Remainder of Fiscal Year	$ 0.1		$ 0.1