Property, Plant and Equipment (Tables)

12 Months Ended

Dec. 31, 2019

Property, Plant and Equipment [Abstract]

Summary of Property, Plant and Equipment

		December 31, 2019				December 31, 2018
(Millions of dollars)	Estimated Useful Life	Cost		Net		Cost		Net
Land		$	598.6	$	598.6	$	591.9	$	591.9
Pipeline and terminal facilities	16 to 25 years	77.5		43.7		73.1		41.6
Retail gasoline stations	3 to 50 years	2,034.4		1,073.6		1,890.6		1,018.5
Buildings	20 to 45 years	60.5		44.9		55.0		41.8
Other	3 to 20 years	115.5		46.5		111.8		54.4
		$	2,886.5	$	1,807.3	$	2,722.4	$	1,748.2