Goodwill and Other Intangible Assets (Tables)

12 Months Ended

Dec. 31, 2019

Goodwill And Intangible Assets Disclosure [Abstract]

Summary of Goodwill

The following table summarizes goodwill activity for the three years in the period ended December 31, 2019 (in millions):

			Accumulated			Goodwill,
	Goodwill		Impairments			Net
Balance at January 1, 2017	$	21.3	$	(11.8	)	$	9.5
No activity in 2017		—		—			—
Balance at December 31, 2017		21.3		(11.8	)		9.5
No activity in 2018		—		—			—
Balance at December 31, 2018		21.3		(11.8	)		9.5
No activity in 2019		—		—			—
Balance at December 31, 2019	$	21.3	$	(11.8	)	$	9.5

Summary of Other Intangible Assets

Information regarding the Company’s other amortizable intangible assets is as follows (in millions):

					Accumulated
	Cost				Amortization
	2019		2018		2019		2018
Customer relationships	$	4.9	$	4.9	$	2.2	$	1.8
Trademarks		1.6		1.6		1.2		0.9
Other		1.6		1.6		1.6		1.5
Total amortizable intangible assets (1)	$	8.1	$	8.1	$	5.0	$	4.2

⁽¹⁾ Amortizable intangible assets are included in “Other Assets.”

Summary of Estimated Intangible Asset Amortization Expense

Estimated intangible asset amortization expense, by year in the aggregate, consists of the following at December 31, 2019

	Amortization
2020	$	0.6
2021		0.3
2022		0.2
2023		0.2
2024		0.2
Thereafter		1.6
Total	$	3.1