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Asset Retirement Obligations (Tables)

12 Months Ended

Dec. 31, 2020

Asset Retirement Obligation [Abstract]

Changes to Asset Retirement Obligation

The following table describes changes to the asset retirement obligation liability (dollars in millions):

		Year Ended December 31,
		2020				2019
Asset retirement obligation at beginning of period		$	27.8			$	30.0
Accretion expense			1.3				1.5
Payments			(0.8	)			(3.5	)
Revisions in estimated cash flows (a)			3.5				(0.2	)
Asset retirement obligation at end of period		$	31.8			$	27.8

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- References

No definition available.

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- Definition

Tabular disclosure of the changes in carrying amount of a liability for asset retirement obligations, for changes such as new obligations, changes in estimates of existing obligations, spending on existing obligations, property dispositions, and foreign currency translation.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 410
-SubTopic 30
-Section 50
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=6393242&loc=d3e13201-110859

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