Business Segments - Schedule of Other Significant Items (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Segment Reporting Information [Line Items]
Accretion of asset retirement obligations	$ 3.4	$ 3.2	$ 3.0
Deferred and noncurrent income tax charges (benefits)	45.1	14.0	2.0
Additions to property, plant and equipment	432.4	503.0	344.1
Total assets at year-end	4,725.8	4,541.6	4,340.1
Operating segments | Marketing
Segment Reporting Information [Line Items]
Accretion of asset retirement obligations	3.4	3.2	3.0
Deferred and noncurrent income tax charges (benefits)	58.4	17.6	(4.5)
Additions to property, plant and equipment	414.6	464.1	289.5
Total assets at year-end	4,534.6	4,326.8	4,061.7
Corporate and Other Assets
Segment Reporting Information [Line Items]
Accretion of asset retirement obligations	0.0	0.0	0.0
Deferred and noncurrent income tax charges (benefits)	(13.3)	(3.6)	6.5
Additions to property, plant and equipment	17.8	38.9	54.6
Total assets at year-end	$ 191.2	$ 214.8	$ 278.4