Property, Plant and Equipment (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Property, Plant and Equipment [Line Items]
Cost	$ 2,886,500	$ 2,722,400
Net	1,807,300	1,748,200
Depreciation expense	151,200	132,500	$ 115,000
Land
Property, Plant and Equipment [Line Items]
Cost	598,600	591,900
Net	598,600	591,900
Pipeline and terminal facilities
Property, Plant and Equipment [Line Items]
Cost	77,500	73,100
Net	43,700	41,600
Retail gasoline stations
Property, Plant and Equipment [Line Items]
Cost	2,034,400	1,890,600
Net	1,073,600	1,018,500
Buildings
Property, Plant and Equipment [Line Items]
Cost	60,500	55,000
Net	44,900	41,800
Other
Property, Plant and Equipment [Line Items]
Cost	115,500	111,800
Net	$ 46,500	$ 54,400
Minimum | Pipeline and terminal facilities
Property, Plant and Equipment [Line Items]
Estimated useful life (in years)	16 years
Minimum | Retail gasoline stations
Property, Plant and Equipment [Line Items]
Estimated useful life (in years)	3 years
Minimum | Buildings
Property, Plant and Equipment [Line Items]
Estimated useful life (in years)	20 years
Minimum | Other
Property, Plant and Equipment [Line Items]
Estimated useful life (in years)	3 years
Maximum | Pipeline and terminal facilities
Property, Plant and Equipment [Line Items]
Estimated useful life (in years)	25 years
Maximum | Retail gasoline stations
Property, Plant and Equipment [Line Items]
Estimated useful life (in years)	50 years
Maximum | Buildings
Property, Plant and Equipment [Line Items]
Estimated useful life (in years)	45 years
Maximum | Other
Property, Plant and Equipment [Line Items]
Estimated useful life (in years)	20 years