Revenues (Narrative) (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2020	Dec. 31, 2019
Disaggregation of Revenue [Line Items]
Trade accounts receivable	$ 161.3	$ 172.9
Receivables related to contracts with customers
Disaggregation of Revenue [Line Items]
Trade accounts receivable	$ 81.5	$ 96.0
RINs
Disaggregation of Revenue [Line Items]
Collection period	5 days
Bulk pipelines sales
Disaggregation of Revenue [Line Items]
Collection period	7 days
Product Sales, Petroleum, Wholesale Rack Sales
Disaggregation of Revenue [Line Items]
Collection period	10 days
Minimum | Petroleum product sales (at retail)
Disaggregation of Revenue [Line Items]
Collection period	2 days
Maximum | Petroleum product sales (at retail)
Disaggregation of Revenue [Line Items]
Collection period	7 days