v3.25.3
ASSET RETIREMENT OBLIGATIONS (Tables)
 9 Months Ended
Sep. 30, 2025
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
September 30		Nine Months Ended
September 30
in millions2025202420252024
Accretion$5.0 $3.7 $14.0 $10.8 
Depreciation2.4 3.2 10.4 8.4 
Total ARO operating costs$7.4 $6.9 $24.4 $19.2 
Schedule of Reconciliations of Asset Retirement Obligations
Reconciliations of the carrying amounts of our ARO liabilities are as follows:
Three Months Ended
September 30		Nine Months Ended
September 30
in millions2025202420252024
ARO liability balance at beginning of period$447.8 $334.1 $427.4 $324.1 
Liabilities incurred6.0 0.0 29.2 0.8 
Liabilities settled 1
(2.7)(3.5)(14.4)(8.3)
Accretion expense5.0 3.7 14.0 10.8 
Revisions, net
(10.0)12.2 (10.1)19.1 
ARO liability balance at end of period$446.1 $346.5 $446.1 $346.5