Commitments and Contingencies (Details) (Narrative) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Loss Contingencies [Line Items]
Accrual for Environmental Loss Contingencies	$ 19.3	$ 24.0
Environmental Remediation Expense	9.0	5.9	$ 8.4
Recorded Third-Party Environmental Recoveries Receivable	7.2	4.1
Recorded Third-Party Environmental Recoveries, Amount	0.7	0.9	$ 0.5
Accounts Receivable [Member]
Loss Contingencies [Line Items]
Recorded Third-Party Environmental Recoveries Receivable	0.5	0.6
Other Noncurrent Assets [Member]
Loss Contingencies [Line Items]
Recorded Third-Party Environmental Recoveries Receivable	$ 6.7	$ 3.5