Business Combinations, Goodwill and Intangible Assets (Tables)

12 Months Ended

Dec. 31, 2020

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,
	2020			2019
Gross carrying value	$	37.2		$	62.4
Accumulated impairment loss:
Beginning balance		(18.4	)		(18.4	)
Impairment loss		—			(25.2	)
Ending balance		(18.4	)		(43.6	)
Net carrying value	$	18.8		$	18.8

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, 2020
Customer relationships		24	$	36.1	$	(14.2	)	$	21.9
Trade name		10		2.4		(0.6	)		1.8
Non-compete agreement		5		5.4		(2.4	)		3.0
Total			$	43.9	$	(17.2	)	$	26.7
As of December 31, 2019
Customer relationships		24	$	36.1	$	(12.7	)	$	23.4
Trade name		10		2.4		(0.3	)		2.1
Non-compete agreement		5		5.4		(1.3	)		4.1
Total			$	43.9	$	(14.3	)	$	29.6

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, 2020 (in millions of dollars):

2021	$	2.8
2022		2.8
2023		2.6
2024		1.8
2025		1.8
Thereafter		14.9
Total	$	26.7