ASSET RETIREMENT OBLIGATIONS (Tables)	12 Months Ended
Dec. 31, 2021
ASSET RETIREMENT OBLIGATIONS [Abstract]
Asset Retirement Obligations Operating Costs	in millions2021 2020 2019 ARO Operating Costs Accretion$ 13.1 $ 12.4 $ 11.0 Depreciation 10.6 8.6 7.1 Total$ 23.7 $ 21.0 $ 18.1
Reconciliations of Asset Retirement Obligations	in millions2021 2020 Asset Retirement Obligations Balance at beginning of year$ 283.2 $ 210.3 Liabilities incurred 19.2 0.4 Liabilities settled (11.0) (12.8) Accretion expense 13.1 12.4 Revisions, net 10.7 72.9 Balance at end of year$ 315.2 $ 283.2

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.

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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