Business Combinations, Goodwill and Intangible Assets (Tables)

12 Months Ended

Dec. 31, 2022

Business Combinations Goodwill And Intangible Assets Disclosure [Abstract]

Schedule of Goodwill

The following table presents the changes in the carrying value of our goodwill (in millions of dollars):

	As of December 31,
	2022			2021
Gross carrying value:
Beginning balance	$	57.7		$	37.2
Warrick acquisition		—			20.5
Warrick impairment		(20.5	)		—
Ending balance		37.2			57.7
Accumulated impairment loss		(18.4	)		(18.4	)
Net carrying value	$	18.8		$	39.3

Schedule of Gross Carrying Amount and Accumulated Amortization By Major Intangible Asset Class

The following table presents the gross carrying amount and accumulated amortization by major intangible asset class (in millions of dollars, except amortization periods):

	Weighted- Average Amortization Period (in years)		Gross Amount		Accumulated Amortization			Intangible Assets, Net
As of December 31, 2022
Customer relationships		19	$	68.1	$	(21.9	)	$	46.2
Trade name		10		2.4		(1.0	)		1.4
Non-compete agreement		5		5.4		(4.6	)		0.8
Favorable lease contracts		120		7.0		(0.1	)		6.9
Total			$	82.9	$	(27.6	)	$	55.3
As of December 31, 2021
Customer relationships		19	$	68.1	$	(17.8	)	$	50.3
Trade name		10		2.4		(0.8	)		1.6
Non-compete agreement		5		5.4		(3.5	)		1.9
Favorable commodity contracts		2		11.0		(4.1	)		6.9
Favorable lease contracts		120		7.0		—			7.0
Total			$	93.9	$	(26.2	)	$	67.7

Schedule of Expected Amortization of Intangible Assets

The following table presents the expected amortization of intangible assets for each of the next five calendar years and thereafter as of December 31, 2022 (in millions of dollars):

2023	$	5.3
2024		4.5
2025		4.5
2026		4.5
2027		4.5
Thereafter		32.0
Total	$	55.3