Employee Benefit Plans (Components Of Net Pension (Expense) Income) (Details) - USD ($) $ in Millions	1 Months Ended	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Retirement Benefits [Abstract]
Service cost		$ (4.0)	$ (3.9)	$ (4.6)
Interest cost		(8.5)	(8.0)	(10.9)
Expected return on plan assets		11.3	11.9	13.4
Recognized net actuarial loss		(2.9)	(2.6)	(4.6)
Prior service cost		(1.7)	0.0	0.0
Settlements	$ (15.3)	0.0	0.0	(15.3)
Net pension expense		$ (5.8)	$ (2.6)	$ (22.0)
Weighted average assumptions for pension costs:
Discount rate used in net pension costs		3.90%	3.40%	3.80%
Rate of compensation increase used in pension costs		3.00%	3.00%	3.50%
Expected return on plan assets		6.40%	6.40%	6.50%
Weighted average assumptions for benefit obligation:
Discount rate used in benefit obligation	3.40%	2.80%	3.90%	3.40%
Rate of compensation increase used in benefit obligation	3.00%	3.40%	3.00%	3.00%