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Commitments and Contingencies (Details) (Narrative) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Sep. 30, 2018
Loss Contingencies [Line Items]
Accrual for Environmental Loss Contingencies	$ 20.5	$ 19.3
Environmental Remediation Expense	15.0	9.0	$ 5.9
Recorded Third-Party Environmental Recoveries Receivable	4.1	7.2
Recorded Third-Party Environmental Recoveries, Amount	$ 3.1	0.7	$ 0.9
BridgeTex [Member]
Loss Contingencies [Line Items]
Equity Method Investment, Ownership Percentage	30.00%			30.00%
Powder Springs Logistics, LLC [Member]
Loss Contingencies [Line Items]
Equity Method Investment, Ownership Percentage	50.00%
Indemnification Agreement [Member] \| Equity Method Investee [Member] \| BridgeTex [Member]
Loss Contingencies [Line Items]
Guarantees, Fair Value Disclosure	$ 16.0
Guarantee of Indebtedness of Others [Member] \| Equity Method Investee [Member] \| Powder Springs Logistics, LLC [Member]
Loss Contingencies [Line Items]
Guarantees, Fair Value Disclosure	$ 0.4
Equity Method Investment, Ownership Percentage	50.00%
Guarantor Obligations, Maximum Exposure, Undiscounted	$ 25.0
Accounts Receivable [Member]
Loss Contingencies [Line Items]
Recorded Third-Party Environmental Recoveries Receivable	2.4	0.5
Other Noncurrent Assets [Member]
Loss Contingencies [Line Items]
Recorded Third-Party Environmental Recoveries Receivable	$ 1.7	$ 6.7