Pension And Postretirement Benefits (Components Of Net Periodic Benefits Cost) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 6.4	$ 5.4	$ 5.9
Interest cost	26.1	32.7	30.1
Expected return on plan assets	(57.5)	(53.7)	(65.6)
Amortization of prior service cost	(0.3)	(0.3)	(0.5)
Amortization of net (gain) loss	19.1	15.3	14.2
Recognized Curtailments Gain/(Loss)	(2.3)	0.0	0.3
Settlement costs	1.7	0.0	0.3
Net periodic benefit cost	(6.8)	(0.6)	(15.3)
Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	0.3	0.3	0.3
Interest cost	0.9	1.1	1.1
Expected return on plan assets	0.0	0.0	0.0
Amortization of prior service cost	(1.1)	(1.1)	(1.0)
Amortization of net (gain) loss	0.0	(0.3)	(0.2)
Recognized Curtailments Gain/(Loss)	0.0	0.0	0.0
Settlement costs	0.0	0.0	0.0
Net periodic benefit cost	$ 0.1	$ 0.0	$ 0.2