v3.26.1
ASSET RETIREMENT OBLIGATIONS (Tables)
 6 Months Ended
Jun. 30, 2026
Asset Retirement Obligation Disclosure [Abstract]  
Schedule of Asset Retirement Obligations Operating Costs
ARO operating costs related to accretion of the liabilities and depreciation of the assets are as follows:
Three Months Ended
June 30		Six Months Ended
June 30
in millions2026202520262025
ARO Operating Costs
Accretion$5.0 $4.8 $10.1 $9.0 
Depreciation3.8 4.0 7.3 8.0 
Total ARO operating costs$8.8 $8.8 $17.4 $17.0 
Schedule of Reconciliations of Asset Retirement Obligations
Reconciliations of the carrying amounts of our ARO liabilities are as follows:
Three Months Ended
June 30		Six Months Ended
June 30
in millions2026202520262025
Asset Retirement Obligations
ARO liability balance at beginning of period
$460.0 $429.5 $456.5 $427.4 
Liabilities incurred0.4 18.2 0.4 23.2 
Liabilities settled
(3.5)(4.7)(6.6)(11.6)
Accretion expense5.0 4.8 10.1 9.0 
Revisions, net
2.6 0.0 4.1 (0.2)
ARO liability balance at end of period
$464.5 $447.8 $464.5 $447.8