XML 43 R31.htm IDEA: XBRL DOCUMENT v3.21.1

Asset Retirement Obligations (ARO) (Tables)

3 Months Ended

Mar. 31, 2021

Asset Retirement Obligation Disclosure [Abstract]

Reconciliation of Beginning and Ending Aggregate Carrying Amount of Asset Retirement Obligation

A reconciliation of the beginning and ending aggregate carrying amount of the ARO is shown in the following table.

(Millions of dollars)						March 31, 2021						December 31, 2020
Balance at beginning of period						$	35.1					$	32.8
Addition for acquisition						1.2						—
Accretion expense						0.6						2.3
Settlements of liabilities						(0.2)						(0.8)
Liabilities incurred						—						0.8
Balance at end of period						$	36.7					$	35.1

X

- References

No definition available.

+ Details

Name:	us-gaap_AssetRetirementObligationDisclosureAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- 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

+ Details

Name:	us-gaap_ScheduleOfChangeInAssetRetirementObligationTableTextBlock
Namespace Prefix:	us-gaap_
Data Type:	nonnum:textBlockItemType
Balance Type:	na
Period Type:	duration