Basis of Presentation Employee Benefits (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 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			$ 9.4
Defined Benefit Plan, Expected Future Employer Contributions, Remainder of Fiscal Year	$ 3.4		3.4
WRAP Plan Liabilities	25.5		25.5		$ 26.8
Rabbi Trust Marketable Securities	23.5		23.5		$ 23.1
Deferred Compensation Mark To Market Adjustments	5.0	$ 0.3	(3.2)	$ 3.7
Change In Deferred Compensation Mark To Market Adjustment	4.7		(6.9)
Marketable Securities, Unrealized Gain (Loss)	3.3	$ (0.8)	0.0	$ (2.7)
Change in Marketable Securities Unrealized Gain Loss	(4.1)		(2.7)
Pension Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Contributions by Employer			2.0
Defined Benefit Plan, Expected Future Employer Contributions, Remainder of Fiscal Year	2.0		2.0
SERP [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Contributions by Employer			7.4
Defined Benefit Plan, Expected Future Employer Contributions, Remainder of Fiscal Year	1.2		1.2
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	$ 0.2		$ 0.2