Retirement, Postretirement And Other Benefit Plans (Schedule Of Asset Fair Value Measurements) (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Defined Benefit Plan Disclosure [Line Items]
Total assets at net asset value	$ 242.2	$ 230.2
Total assets at fair value and net asset value	374.3	355.5
Cash
Defined Benefit Plan Disclosure [Line Items]
Total assets at fair value	8.3	5.8
Mutual Fund
Defined Benefit Plan Disclosure [Line Items]
Total assets at fair value	82.5	69.9
Exchange Traded Funds
Defined Benefit Plan Disclosure [Line Items]
Total assets at fair value	18.6	26.1
Common Stock
Defined Benefit Plan Disclosure [Line Items]
Total assets at fair value	21.5	16.0
Short Term Investment Fund, measured at NAV
Defined Benefit Plan Disclosure [Line Items]
Total assets at fair value	1.2	1.4
Insurance Contracts, measured at NAV
Defined Benefit Plan Disclosure [Line Items]
Total assets at fair value		6.1
Common Collective Trust, measured at NAV
Defined Benefit Plan Disclosure [Line Items]
Total assets at net asset value	206.8	195.2
Partnership, measured at NAV
Defined Benefit Plan Disclosure [Line Items]
Total assets at net asset value	9.9	8.6
Hedge Fund, measured at NAV
Defined Benefit Plan Disclosure [Line Items]
Total assets at net asset value	25.5	26.4
Level 1
Defined Benefit Plan Disclosure [Line Items]
Total assets at fair value	132.1	119.2
Level 1 | Cash
Defined Benefit Plan Disclosure [Line Items]
Total assets at fair value	8.3	5.8
Level 1 | Mutual Fund
Defined Benefit Plan Disclosure [Line Items]
Total assets at fair value	82.5	69.9
Level 1 | Exchange Traded Funds
Defined Benefit Plan Disclosure [Line Items]
Total assets at fair value	18.6	26.1
Level 1 | Common Stock
Defined Benefit Plan Disclosure [Line Items]
Total assets at fair value	21.5	16.0
Level 1 | Short Term Investment Fund, measured at NAV
Defined Benefit Plan Disclosure [Line Items]
Total assets at fair value	1.2	1.4
Level 1 | Insurance Contracts, measured at NAV
Defined Benefit Plan Disclosure [Line Items]
Total assets at fair value		0.0
Level 2
Defined Benefit Plan Disclosure [Line Items]
Total assets at fair value	0.0	0.0
Level 2 | Cash
Defined Benefit Plan Disclosure [Line Items]
Total assets at fair value	0.0	0.0
Level 2 | Mutual Fund
Defined Benefit Plan Disclosure [Line Items]
Total assets at fair value	0.0	0.0
Level 2 | Exchange Traded Funds
Defined Benefit Plan Disclosure [Line Items]
Total assets at fair value	0.0	0.0
Level 2 | Common Stock
Defined Benefit Plan Disclosure [Line Items]
Total assets at fair value	0.0	0.0
Level 2 | Short Term Investment Fund, measured at NAV
Defined Benefit Plan Disclosure [Line Items]
Total assets at fair value	0.0	0.0
Level 2 | Insurance Contracts, measured at NAV
Defined Benefit Plan Disclosure [Line Items]
Total assets at fair value		0.0
Level 3
Defined Benefit Plan Disclosure [Line Items]
Total assets at fair value	0.0	6.1
Level 3 | Cash
Defined Benefit Plan Disclosure [Line Items]
Total assets at fair value	0.0	0.0
Level 3 | Mutual Fund
Defined Benefit Plan Disclosure [Line Items]
Total assets at fair value	0.0	0.0
Level 3 | Exchange Traded Funds
Defined Benefit Plan Disclosure [Line Items]
Total assets at fair value	0.0	0.0
Level 3 | Common Stock
Defined Benefit Plan Disclosure [Line Items]
Total assets at fair value	0.0	0.0
Level 3 | Short Term Investment Fund, measured at NAV
Defined Benefit Plan Disclosure [Line Items]
Total assets at fair value	0.0	0.0
Level 3 | Insurance Contracts, measured at NAV
Defined Benefit Plan Disclosure [Line Items]
Total assets at fair value	$ 0.0	$ 6.1